diff --git a/.gitignore b/.gitignore
index 21664bc..25e7b7f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,4 +25,16 @@ Thumbs.db
 # ===== Docker / NAS =====
 docker-data/
 *.bak
-*.tmp
\ No newline at end of file
+*.tmp
+
+# Python
+__pycache__/
+*.pyc
+*.pyo
+*.pyd
+
+# Virtual environments
+.venv/
+venv/
+env/
+backend/.venv/
diff --git a/backend/app/core/fiscal_lock.py b/backend/app/core/fiscal_lock.py
new file mode 100644
index 0000000..646ad2e
--- /dev/null
+++ b/backend/app/core/fiscal_lock.py
@@ -0,0 +1,19 @@
+from fastapi import HTTPException
+from app.core.database import get_connection
+
+def check_fiscal_year_unlocked(journal_date):
+    fiscal_year = journal_date.year
+
+    with get_connection() as conn, conn.cursor() as cur:
+        cur.execute("""
+            SELECT is_locked
+              FROM fiscal_year_locks
+             WHERE fiscal_year = %s
+        """, (fiscal_year,))
+        row = cur.fetchone()
+
+        if row and row["is_locked"]:
+            raise HTTPException(
+                status_code=400,
+                detail="この会計年度は既に確定されているため、仕訳を変更できません。"
+            )
diff --git a/backend/app/main.py b/backend/app/main.py
index 0e5af8d..6ecace0 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -10,6 +10,16 @@ app = FastAPI(
     title="日本小規模企業向け会計システム"
 )
 
+from fastapi.middleware.cors import CORSMiddleware
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],  # 本地开发先用 *
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
 @app.exception_handler(ValidationError)
 async def validation_exception_handler(request: Request, exc: ValidationError):
     # ここでは最初のエラーだけ簡潔に返す（必要に応じて整形）
@@ -45,3 +55,13 @@ app.include_router(trial_balance_router)
 from app.modules.opening_balances.router import router as opening_router
 app.include_router(opening_router)
 
+from app.modules.general_ledger.router import router as general_ledger_router
+app.include_router(general_ledger_router)
+
+from app.modules.opening_balances.lock_router import router as opening_balance_lock_router
+app.include_router(opening_balance_lock_router)
+
+
+
+
+
diff --git a/backend/app/modules/general_ledger/__init__.py b/backend/app/modules/general_ledger/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/backend/app/modules/general_ledger/router.py b/backend/app/modules/general_ledger/router.py
new file mode 100644
index 0000000..31476a4
--- /dev/null
+++ b/backend/app/modules/general_ledger/router.py
@@ -0,0 +1,28 @@
+from fastapi import APIRouter, HTTPException, Query
+from app.modules.general_ledger.service import fetch_general_ledger
+
+router = APIRouter(
+    prefix="/general-ledger",
+    tags=["元帳"]
+)
+
+@router.get("", summary="元帳取得（科目別）")
+def get_general_ledger(
+    account_id: int = Query(...),
+    date_from: str = Query(...),
+    date_to: str = Query(...)
+):
+    if date_from > date_to:
+        raise HTTPException(status_code=400, detail="期間指定が不正です。")
+
+    result = fetch_general_ledger(account_id, date_from, date_to)
+    if result is None:
+        raise HTTPException(status_code=400, detail="科目が存在しません。")
+
+    return {
+        "period": {
+            "from": date_from,
+            "to": date_to
+        },
+        **result
+    }
diff --git a/backend/app/modules/general_ledger/service.py b/backend/app/modules/general_ledger/service.py
new file mode 100644
index 0000000..3c70b24
--- /dev/null
+++ b/backend/app/modules/general_ledger/service.py
@@ -0,0 +1,53 @@
+from decimal import Decimal
+from app.core.database import get_connection
+from app.modules.general_ledger.sql import GENERAL_LEDGER_SQL
+
+def D(x) -> Decimal:
+    return Decimal(str(x or 0))
+
+def fetch_general_ledger(account_id: int, date_from: str, date_to: str):
+
+    with get_connection() as conn, conn.cursor() as cur:
+
+        # ① 科目确认
+        cur.execute("""
+            SELECT account_code, account_name
+              FROM accounts
+             WHERE account_id = %s
+               AND is_active = true
+        """, (account_id,))
+        acc = cur.fetchone()
+        if not acc:
+            return None
+
+        # ② 元帳明细
+        cur.execute(
+            GENERAL_LEDGER_SQL,
+            {
+                "account_id": account_id,
+                "date_from": date_from,
+                "date_to": date_to
+            }
+        )
+        rows = cur.fetchall()
+
+        balance = Decimal("0")
+        lines = []
+
+        for r in rows:
+            balance += D(r["debit"]) - D(r["credit"])
+            lines.append({
+                "journal_date": r["journal_date"],
+                "description": r["description"],
+                "debit": str(D(r["debit"])),
+                "credit": str(D(r["credit"])),
+                "balance": str(balance)
+            })
+
+    return {
+        "account": {
+            "account_code": acc["account_code"],
+            "account_name": acc["account_name"]
+        },
+        "lines": lines
+    }
diff --git a/backend/app/modules/general_ledger/sql.py b/backend/app/modules/general_ledger/sql.py
new file mode 100644
index 0000000..6ace459
--- /dev/null
+++ b/backend/app/modules/general_ledger/sql.py
@@ -0,0 +1,14 @@
+# sql.py
+GENERAL_LEDGER_SQL = """
+SELECT
+    j.journal_date,
+    j.description,
+    l.debit,
+    l.credit
+FROM journal_lines l
+JOIN journal_entries j
+  ON j.journal_id = l.journal_id
+WHERE l.account_id = %(account_id)s
+  AND j.journal_date BETWEEN %(date_from)s AND %(date_to)s
+ORDER BY j.journal_date, l.line_id;
+"""
diff --git a/backend/app/modules/journals/router.py b/backend/app/modules/journals/router.py
index d555a4b..6a2adc6 100644
--- a/backend/app/modules/journals/router.py
+++ b/backend/app/modules/journals/router.py
@@ -4,6 +4,8 @@ from typing import List
 from decimal import Decimal, InvalidOperation
 from psycopg.errors import ForeignKeyViolation, CheckViolation
 from app.core.database import get_connection
+from app.core.fiscal_lock import check_fiscal_year_unlocked
+from datetime import date
 
 router = APIRouter(prefix="/journals", tags=["仕訳"])
 
@@ -109,3 +111,74 @@ def create_journal(data: JournalCreate):
             raise HTTPException(status_code=400, detail="科目IDが不正です。")
         except CheckViolation:
             raise HTTPException(status_code=400, detail="金額の指定が不正です。")
+
+
+@router.put("/{journal_id}", summary="仕訳修正")
+def update_journal(journal_id: int, data: JournalCreate):
+
+    with get_connection() as conn, conn.cursor() as cur:
+
+        # ① 先取原仕訳の日付
+        cur.execute(
+            "SELECT journal_date FROM journal_entries WHERE journal_id = %s",
+            (journal_id,)
+        )
+        row = cur.fetchone()
+        if not row:
+            raise HTTPException(status_code=404, detail="仕訳が存在しません。")
+
+        # 🔒 ② 这里！！年度锁定检查
+        check_fiscal_year_unlocked(row["journal_date"])
+
+        # ③ 删除旧明细
+        cur.execute(
+            "DELETE FROM journal_lines WHERE journal_id = %s",
+            (journal_id,)
+        )
+
+        # ④ 更新ヘッダ
+        cur.execute(
+            "UPDATE journal_entries SET journal_date=%s, description=%s WHERE journal_id=%s",
+            (data.journal_date, data.description, journal_id)
+        )
+
+        # ⑤ 插入新明细
+        for l in data.lines:
+            cur.execute(
+                """INSERT INTO journal_lines (journal_id, account_id, debit, credit)
+                   VALUES (%s, %s, %s, %s)""",
+                (journal_id, l.account_id, l.debit, l.credit)
+            )
+
+        conn.commit()
+        return {"message": "仕訳を修正しました。"}
+
+@router.delete("/{journal_id}", summary="仕訳削除")
+def delete_journal(journal_id: int):
+
+    with get_connection() as conn, conn.cursor() as cur:
+
+        # ① 先取日付
+        cur.execute(
+            "SELECT journal_date FROM journal_entries WHERE journal_id = %s",
+            (journal_id,)
+        )
+        row = cur.fetchone()
+        if not row:
+            raise HTTPException(status_code=404, detail="仕訳が存在しません。")
+
+        # 🔒 ② 年度锁定检查（就在这里）
+        check_fiscal_year_unlocked(row["journal_date"])
+
+        # ③ 删除
+        cur.execute(
+            "DELETE FROM journal_lines WHERE journal_id = %s",
+            (journal_id,)
+        )
+        cur.execute(
+            "DELETE FROM journal_entries WHERE journal_id = %s",
+            (journal_id,)
+        )
+
+        conn.commit()
+        return {"message": "仕訳を削除しました。"}
\ No newline at end of file
diff --git a/backend/app/modules/ledger/router.py b/backend/app/modules/ledger/router.py
index 5419427..ab3ebb5 100644
--- a/backend/app/modules/ledger/router.py
+++ b/backend/app/modules/ledger/router.py
@@ -1,109 +1,107 @@
 from fastapi import APIRouter, HTTPException, Query
-from typing import Optional, List, Dict, Any
 from decimal import Decimal
-from datetime import date
 from app.core.database import get_connection
 
-router = APIRouter(prefix="/ledger", tags=["元帳"])
+router = APIRouter(
+    prefix="/general-ledger",
+    tags=["元帳"]
+)
 
-def to_decimal(x) -> Decimal:
-    if isinstance(x, Decimal):
-        return x
+
+def D(x) -> Decimal:
     return Decimal(str(x or 0))
 
-@router.get("/{account_id}", summary="科目別元帳（残高推移）")
-def get_ledger(
-    account_id: int,
-    date_from: Optional[str] = Query(None, description="YYYY-MM-DD"),
-    date_to: Optional[str] = Query(None, description="YYYY-MM-DD"),
+
+@router.get("", summary="元帳取得（期首残高対応）")
+def get_general_ledger(
+    account_id: int = Query(..., description="科目ID"),
+    fiscal_year: int = Query(..., description="会計年度（例：2025）"),
+    date_from: str = Query(..., description="YYYY-MM-DD"),
+    date_to: str = Query(..., description="YYYY-MM-DD"),
 ):
-    # 1) 科目存在チェック
+    if date_from > date_to:
+        raise HTTPException(status_code=400, detail="期間指定が不正です。")
+
     with get_connection() as conn, conn.cursor() as cur:
+
+        # ----------------------------
+        # 科目存在確認
+        # ----------------------------
         cur.execute("""
-            SELECT account_id, account_code, account_name, account_type
+            SELECT account_code, account_name
               FROM accounts
              WHERE account_id = %s
+               AND is_active = true
         """, (account_id,))
-        account = cur.fetchone()
-        if not account:
-            raise HTTPException(status_code=404, detail="指定した科目が見つかりません。")
+        acc = cur.fetchone()
 
-        # 2) 期間デフォルト（最小〜最大）
-        if not date_from:
-            cur.execute("""
-                SELECT MIN(j.journal_date) AS min_d
-                  FROM journal_entries j
-                  JOIN journal_lines l ON l.journal_id = j.journal_id
-                 WHERE l.account_id = %s
-            """, (account_id,))
-            row = cur.fetchone()
-            date_from = (row["min_d"] or date.today()).isoformat()
+        if not acc:
+            raise HTTPException(status_code=400, detail="指定された科目は存在しません。")
 
-        if not date_to:
-            cur.execute("""
-                SELECT MAX(j.journal_date) AS max_d
-                  FROM journal_entries j
-                  JOIN journal_lines l ON l.journal_id = j.journal_id
-                 WHERE l.account_id = %s
-            """, (account_id,))
-            row = cur.fetchone()
-            date_to = (row["max_d"] or date.today()).isoformat()
-
-        # 3) 期首残高（date_from より前）
+        # ----------------------------
+        # 期首残高（opening_balances）
+        # ----------------------------
         cur.execute("""
-            SELECT COALESCE(SUM(l.debit - l.credit), 0) AS opening
-              FROM journal_lines l
-              JOIN journal_entries j ON j.journal_id = l.journal_id
-             WHERE l.account_id = %s
-               AND j.journal_date < %s
-        """, (account_id, date_from))
-        opening = to_decimal(cur.fetchone()["opening"])
+            SELECT
+                COALESCE(opening_debit, 0) - COALESCE(opening_credit, 0) AS opening
+              FROM opening_balances
+             WHERE fiscal_year = %s
+               AND account_id = %s
+        """, (fiscal_year, account_id))
 
-        # 4) 期間内明細
+        row = cur.fetchone()
+        opening_balance = D(row["opening"]) if row else D(0)
+
+        # ----------------------------
+        # 期間内仕訳取得
+        # ----------------------------
         cur.execute("""
-            SELECT j.journal_date, j.journal_id, j.description,
-                   l.debit, l.credit
-              FROM journal_lines l
-              JOIN journal_entries j ON j.journal_id = l.journal_id
+            SELECT
+                j.journal_date,
+                j.description,
+                l.debit,
+                l.credit
+              FROM journal_entries j
+              JOIN journal_lines l
+                ON l.journal_id = j.journal_id
              WHERE l.account_id = %s
                AND j.journal_date BETWEEN %s AND %s
-             ORDER BY j.journal_date, j.journal_id, l.line_id
+             ORDER BY j.journal_date, l.line_id
         """, (account_id, date_from, date_to))
+
         rows = cur.fetchall()
 
-    # 5) 残高推移の計算（借方−貸方）
-    balance = opening
-    out_rows: List[Dict[str, Any]] = []
-    total_debit = Decimal("0")
-    total_credit = Decimal("0")
+        # ----------------------------
+        # 累計残高計算
+        # ----------------------------
+        balance = opening_balance
+        lines = []
 
-    for r in rows:
-        d = to_decimal(r["debit"])
-        c = to_decimal(r["credit"])
-        total_debit += d
-        total_credit += c
-        balance += (d - c)
-        out_rows.append({
-            "date": r["journal_date"].isoformat(),
-            "journal_id": r["journal_id"],
-            "description": r["description"],
-            "debit": str(d),
-            "credit": str(c),
-            "balance": str(balance)  # 借方残を正とする（借方−貸方）
-        })
+        for r in rows:
+            debit = D(r["debit"])
+            credit = D(r["credit"])
+            balance += debit - credit
 
-    result = {
+            lines.append({
+                "journal_date": r["journal_date"],
+                "description": r["description"],
+                "debit": str(debit),
+                "credit": str(credit),
+                "balance": str(balance),
+            })
+
+    return {
         "account": {
-            "id": account["account_id"],
-            "code": account["account_code"],
-            "name": account["account_name"],
-            "type": account["account_type"],
+            "account_id": account_id,
+            "account_code": acc["account_code"],
+            "account_name": acc["account_name"],
         },
-        "period": {"from": date_from, "to": date_to},
-        "opening_balance": str(opening),
-        "total_debit": str(total_debit),
-        "total_credit": str(total_credit),
+        "fiscal_year": fiscal_year,
+        "period": {
+            "from": date_from,
+            "to": date_to
+        },
+        "opening_balance": str(opening_balance),
+        "lines": lines,
         "closing_balance": str(balance),
-        "rows": out_rows
     }
-    return result
diff --git a/backend/app/modules/opening_balances/lock_router.py b/backend/app/modules/opening_balances/lock_router.py
new file mode 100644
index 0000000..527c2ed
--- /dev/null
+++ b/backend/app/modules/opening_balances/lock_router.py
@@ -0,0 +1,27 @@
+from fastapi import APIRouter, HTTPException
+from pydantic import BaseModel
+from app.core.database import get_connection
+
+router = APIRouter(
+    prefix="/opening-balances",
+    tags=["期首残高"]
+)
+
+class LockRequest(BaseModel):
+    fiscal_year: int
+
+@router.post("/lock", summary="期首残高年度確定")
+def lock_fiscal_year(req: LockRequest):
+
+    with get_connection() as conn, conn.cursor() as cur:
+        cur.execute("""
+            INSERT INTO fiscal_year_locks (fiscal_year, is_locked)
+            VALUES (%s, true)
+            ON CONFLICT (fiscal_year)
+            DO UPDATE SET
+                is_locked = true,
+                locked_at = CURRENT_TIMESTAMP
+        """, (req.fiscal_year,))
+        conn.commit()
+
+    return {"message": "期首残高を確定しました。"}
diff --git a/backend/app/modules/opening_balances/router.py b/backend/app/modules/opening_balances/router.py
index 4b40f4a..1103c29 100644
--- a/backend/app/modules/opening_balances/router.py
+++ b/backend/app/modules/opening_balances/router.py
@@ -1,55 +1,108 @@
-# backend/app/modules/opening_balances/router.py
-from fastapi import APIRouter, HTTPException
-from psycopg.errors import ForeignKeyViolation
+from fastapi import APIRouter, HTTPException, Query
+from pydantic import BaseModel
+from typing import List
+from decimal import Decimal
+
 from app.core.database import get_connection
-from app.modules.opening_balances.schema import OpeningBalanceCreate
 
-router = APIRouter(
-    prefix="/opening-balances",
-    tags=["期首残高"]
-)
-
-@router.post("/", summary="期首残高 登録/更新")
-def upsert_opening_balance(data: OpeningBalanceCreate):
-    try:
-        with get_connection() as conn, conn.cursor() as cur:
-            cur.execute("""
-                INSERT INTO opening_balances
-                    (fiscal_year, account_id, opening_debit, opening_credit)
-                VALUES (%s, %s, %s, %s)
-                ON CONFLICT (fiscal_year, account_id)
-                DO UPDATE SET
-                    opening_debit = EXCLUDED.opening_debit,
-                    opening_credit = EXCLUDED.opening_credit
-            """, (
-                data.fiscal_year,
-                data.account_id,
-                data.opening_debit,
-                data.opening_credit
-            ))
-            conn.commit()
-        return {"result": "ok"}
-
-    except ForeignKeyViolation:
-        raise HTTPException(
-            status_code=400,
-            detail="存在しない科目が指定されています"
-        )
+router = APIRouter(prefix="/opening-balances", tags=["期首残高"])
 
 
-@router.get("/{fiscal_year}", summary="期首残高一覧取得")
-def list_opening_balances(fiscal_year: int):
+# ---------- Models ----------
+
+class OpeningBalanceItem(BaseModel):
+    account_id: int
+    debit: Decimal = Decimal("0")
+    credit: Decimal = Decimal("0")
+
+
+class OpeningBalanceRequest(BaseModel):
+    fiscal_year: int
+    balances: List[OpeningBalanceItem]
+
+
+# ---------- GET：期首残高取得 ----------
+
+@router.get("", summary="期首残高取得")
+def get_opening_balances(
+    fiscal_year: int = Query(..., description="会計年度（例：2025）")
+):
     with get_connection() as conn, conn.cursor() as cur:
         cur.execute("""
             SELECT
+                a.account_id,
                 a.account_code,
                 a.account_name,
                 a.account_type,
-                ob.opening_debit,
-                ob.opening_credit
-            FROM opening_balances ob
-            JOIN accounts a ON a.account_id = ob.account_id
-            WHERE ob.fiscal_year = %s
+                COALESCE(o.opening_debit, 0)  AS opening_debit,
+                COALESCE(o.opening_credit, 0) AS opening_credit
+            FROM accounts a
+            LEFT JOIN opening_balances o
+              ON o.account_id = a.account_id
+             AND o.fiscal_year = %s
+            WHERE a.is_active = true
             ORDER BY a.account_code
         """, (fiscal_year,))
         return cur.fetchall()
+
+
+# ---------- POST：期首残高保存 ----------
+
+@router.post("", summary="期首残高保存")
+def save_opening_balances(req: OpeningBalanceRequest):
+
+    # 年度锁定チェック
+    cur.execute("""
+        SELECT is_locked
+            FROM fiscal_year_locks
+            WHERE fiscal_year = %s
+    """, (req.fiscal_year,))
+
+    row = cur.fetchone()
+    if row and row["is_locked"]:
+        raise HTTPException(
+            status_code=400,
+            detail="この会計年度の期首残高は既に確定されています。"
+        )
+
+    total_debit = Decimal("0")
+    total_credit = Decimal("0")
+
+    for b in req.balances:
+        total_debit += b.debit
+        total_credit += b.credit
+
+    if total_debit != total_credit:
+        raise HTTPException(
+            status_code=400,
+            detail="借方合計と貸方合計が一致していません。"
+        )
+
+    with get_connection() as conn, conn.cursor() as cur:
+
+        # 既存データ削除（年度単位）
+        cur.execute("""
+            DELETE FROM opening_balances
+             WHERE fiscal_year = %s
+        """, (req.fiscal_year,))
+
+        # 再登録
+        for b in req.balances:
+            if b.debit == 0 and b.credit == 0:
+                continue
+
+            cur.execute("""
+                INSERT INTO opening_balances
+                    (fiscal_year, account_id, opening_debit, opening_credit)
+                VALUES
+                    (%s, %s, %s, %s)
+            """, (
+                req.fiscal_year,
+                b.account_id,
+                b.debit,
+                b.credit
+            ))
+
+        conn.commit()
+
+    return {"message": "期首残高を保存しました。"}
diff --git a/backend/app/modules/trial_balance/router.py b/backend/app/modules/trial_balance/router.py
index 73ad0df..531327a 100644
--- a/backend/app/modules/trial_balance/router.py
+++ b/backend/app/modules/trial_balance/router.py
@@ -2,6 +2,7 @@ from fastapi import APIRouter, HTTPException, Query
 from decimal import Decimal
 from typing import Dict, Any, List
 from app.core.database import get_connection
+from app.modules.trial_balance.service import fetch_trial_balance
 
 router = APIRouter(prefix="/trial-balance", tags=["試算表"])
 
@@ -10,12 +11,23 @@ def D(x) -> Decimal:
 
 @router.get("", summary="試算表（全科目）")
 def get_trial_balance(
+    fiscal_year: int = Query(..., description="会計年度（例: 2025）"),
     date_from: str = Query(..., description="YYYY-MM-DD"),
     date_to: str = Query(..., description="YYYY-MM-DD"),
 ):
     if date_from > date_to:
         raise HTTPException(status_code=400, detail="期間指定が不正です。")
 
+    result = fetch_trial_balance(date_from, date_to)
+
+    return {
+        "period": {
+            "from": date_from,
+            "to": date_to
+        },
+        **result
+    }
+
     with get_connection() as conn, conn.cursor() as cur:
 
         # 全科目取得
@@ -37,15 +49,18 @@ def get_trial_balance(
         for acc in accounts:
             aid = acc["account_id"]
 
-            # 期首残高
+            # 期首残高（opening_balances）
             cur.execute("""
-                SELECT COALESCE(SUM(l.debit - l.credit), 0) AS opening
-                  FROM journal_lines l
-                  JOIN journal_entries j ON j.journal_id = l.journal_id
-                 WHERE l.account_id = %s
-                   AND j.journal_date < %s
-            """, (aid, date_from))
-            opening = D(cur.fetchone()["opening"])
+                SELECT
+                    COALESCE(opening_debit, 0) - COALESCE(opening_credit, 0) AS opening
+                FROM opening_balances
+                WHERE fiscal_year = %s
+                AND account_id = %s
+            """, (fiscal_year, aid))
+
+            row = cur.fetchone()
+            opening = D(row["opening"]) if row else D(0)
+
 
             # 当期
             cur.execute("""
diff --git a/backend/app/modules/trial_balance/service.py b/backend/app/modules/trial_balance/service.py
new file mode 100644
index 0000000..9a06427
--- /dev/null
+++ b/backend/app/modules/trial_balance/service.py
@@ -0,0 +1,81 @@
+# backend/app/modules/trial_balance/service.py
+from decimal import Decimal
+from typing import Dict, Any, List
+from app.core.database import get_connection
+
+def D(x) -> Decimal:
+    return Decimal(str(x or 0))
+
+def fetch_trial_balance(date_from: str, date_to: str):
+
+    with get_connection() as conn, conn.cursor() as cur:
+
+        cur.execute("""
+            SELECT account_id, account_code, account_name, account_type
+              FROM accounts
+             WHERE is_active = true
+             ORDER BY account_code
+        """)
+        accounts = cur.fetchall()
+
+        result_accounts: List[Dict[str, Any]] = []
+
+        total_opening = Decimal("0")
+        total_debit = Decimal("0")
+        total_credit = Decimal("0")
+        total_closing = Decimal("0")
+
+        for acc in accounts:
+            aid = acc["account_id"]
+
+            # 期首
+            cur.execute("""
+                SELECT COALESCE(SUM(l.debit - l.credit), 0) AS opening
+                  FROM journal_lines l
+                  JOIN journal_entries j ON j.journal_id = l.journal_id
+                 WHERE l.account_id = %s
+                   AND j.journal_date < %s
+            """, (aid, date_from))
+            opening = D(cur.fetchone()["opening"])
+
+            # 当期
+            cur.execute("""
+                SELECT
+                    COALESCE(SUM(l.debit), 0) AS debit,
+                    COALESCE(SUM(l.credit), 0) AS credit
+                  FROM journal_lines l
+                  JOIN journal_entries j ON j.journal_id = l.journal_id
+                 WHERE l.account_id = %s
+                   AND j.journal_date BETWEEN %s AND %s
+            """, (aid, date_from, date_to))
+            row = cur.fetchone()
+            debit = D(row["debit"])
+            credit = D(row["credit"])
+
+            closing = opening + debit - credit
+
+            total_opening += opening
+            total_debit += debit
+            total_credit += credit
+            total_closing += closing
+
+            result_accounts.append({
+                "account_id": aid,
+                "account_code": acc["account_code"],
+                "account_name": acc["account_name"],
+                "account_type": acc["account_type"],
+                "opening_balance": str(opening),
+                "debit": str(debit),
+                "credit": str(credit),
+                "closing_balance": str(closing),
+            })
+
+    return {
+        "totals": {
+            "opening_balance": str(total_opening),
+            "debit": str(total_debit),
+            "credit": str(total_credit),
+            "closing_balance": str(total_closing)
+        },
+        "accounts": result_accounts
+    }
diff --git a/backend/app/modules/trial_balance/sql.py b/backend/app/modules/trial_balance/sql.py
new file mode 100644
index 0000000..47a1bc0
--- /dev/null
+++ b/backend/app/modules/trial_balance/sql.py
@@ -0,0 +1,84 @@
+# backend/app/modules/trial_balance/sql.py
+
+TRIAL_BALANCE_SQL = """
+WITH accounts_base AS (
+    SELECT
+        a.account_id,
+        a.account_code,
+        a.account_name,
+        a.account_type
+    FROM accounts a
+    WHERE a.is_active = true
+),
+
+opening AS (
+    SELECT
+        jl.account_id,
+        SUM(jl.debit)  AS opening_debit,
+        SUM(jl.credit) AS opening_credit
+    FROM journal_entries je
+    JOIN journal_lines jl ON jl.journal_id = je.journal_id
+    WHERE je.description = '前期残高'
+      AND je.journal_date = %(start_date)s
+    GROUP BY jl.account_id
+),
+
+period AS (
+    SELECT
+        jl.account_id,
+        SUM(jl.debit)  AS period_debit,
+        SUM(jl.credit) AS period_credit
+    FROM journal_entries je
+    JOIN journal_lines jl ON jl.journal_id = je.journal_id
+    WHERE je.journal_date BETWEEN %(start_date)s AND %(end_date)s
+      AND je.description <> '前期残高'
+    GROUP BY jl.account_id
+)
+
+SELECT
+    a.account_code,
+    a.account_name,
+    a.account_type,
+
+    COALESCE(o.opening_debit, 0)  AS opening_debit,
+    COALESCE(o.opening_credit, 0) AS opening_credit,
+    COALESCE(p.period_debit, 0)   AS period_debit,
+    COALESCE(p.period_credit, 0)  AS period_credit,
+
+    CASE
+        WHEN (
+            COALESCE(o.opening_debit, 0)
+          - COALESCE(o.opening_credit, 0)
+          + COALESCE(p.period_debit, 0)
+          - COALESCE(p.period_credit, 0)
+        ) > 0
+        THEN (
+            COALESCE(o.opening_debit, 0)
+          - COALESCE(o.opening_credit, 0)
+          + COALESCE(p.period_debit, 0)
+          - COALESCE(p.period_credit, 0)
+        )
+        ELSE 0
+    END AS closing_debit,
+
+    CASE
+        WHEN (
+            COALESCE(o.opening_debit, 0)
+          - COALESCE(o.opening_credit, 0)
+          + COALESCE(p.period_debit, 0)
+          - COALESCE(p.period_credit, 0)
+        ) < 0
+        THEN ABS(
+            COALESCE(o.opening_debit, 0)
+          - COALESCE(o.opening_credit, 0)
+          + COALESCE(p.period_debit, 0)
+          - COALESCE(p.period_credit, 0)
+        )
+        ELSE 0
+    END AS closing_credit
+
+FROM accounts_base a
+LEFT JOIN opening o ON o.account_id = a.account_id
+LEFT JOIN period  p ON p.account_id = a.account_id
+ORDER BY a.account_code;
+"""
diff --git a/frontend/css/style.css b/frontend/css/style.css
index 32eb461..534a387 100644
--- a/frontend/css/style.css
+++ b/frontend/css/style.css
@@ -1,14 +1,23 @@
 body {
-  font-family: system-ui, -apple-system, BlinkMacSystemFont;
-  margin: 20px;
+  font-family: sans-serif;
 }
 
 table {
-  margin-top: 10px;
   border-collapse: collapse;
+  width: 100%;
 }
 
 th,
 td {
-  padding: 6px 10px;
+  border: 1px solid #999;
+  padding: 4px 8px;
+}
+
+th {
+  background: #eee;
+}
+
+a {
+  color: blue;
+  text-decoration: none;
 }
diff --git a/frontend/index.html b/frontend/index.html
index 3047479..8880463 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -2,15 +2,35 @@
 <html lang="ja">
   <head>
     <meta charset="UTF-8" />
-    <title>NJTS 会計システム</title>
+    <title>試算表</title>
     <link rel="stylesheet" href="css/style.css" />
   </head>
   <body>
-    <h1>NJTS 会計システム</h1>
+    <h1>試算表</h1>
 
-    <ul>
-      <li><a href="accounts.html">科目マスタ</a></li>
-      <li><a href="trial-balance.html">試算表</a></li>
-    </ul>
+    <label>
+      期間：
+      <input type="date" id="from" />
+      〜
+      <input type="date" id="to" />
+    </label>
+    <button onclick="loadTrialBalance()">表示</button>
+
+    <table id="trial-table">
+      <thead>
+        <tr>
+          <th>科目コード</th>
+          <th>科目名</th>
+          <th>期首</th>
+          <th>借方</th>
+          <th>贷方</th>
+          <th>期末</th>
+        </tr>
+      </thead>
+      <tbody></tbody>
+    </table>
+
+    <script src="js/api.js"></script>
+    <script src="js/trial_balance.js"></script>
   </body>
 </html>
diff --git a/frontend/journal.html b/frontend/journal.html
new file mode 100644
index 0000000..2300707
--- /dev/null
+++ b/frontend/journal.html
@@ -0,0 +1,47 @@
+<!DOCTYPE html>
+<html lang="ja">
+  <head>
+    <meta charset="UTF-8" />
+    <title>仕訳入力</title>
+    <link rel="stylesheet" href="css/style.css" />
+  </head>
+  <body>
+    <h1>仕訳入力</h1>
+
+    <label>
+      日付：
+      <input type="date" id="journal-date" />
+    </label>
+
+    <br /><br />
+
+    <label>
+      摘要：
+      <input type="text" id="description" size="40" />
+    </label>
+
+    <br /><br />
+
+    <table id="lines-table">
+      <thead>
+        <tr>
+          <th>科目ID</th>
+          <th>借方</th>
+          <th>贷方</th>
+          <th></th>
+        </tr>
+      </thead>
+      <tbody></tbody>
+    </table>
+
+    <button onclick="addLine()">＋ 行追加</button>
+
+    <br /><br />
+
+    <button onclick="submitJournal()">保存</button>
+    <a href="index.html">← 戻る</a>
+
+    <script src="js/api.js"></script>
+    <script src="js/journal.js"></script>
+  </body>
+</html>
diff --git a/frontend/js/api.js b/frontend/js/api.js
index f37f727..6edbfcb 100644
--- a/frontend/js/api.js
+++ b/frontend/js/api.js
@@ -1,10 +1,13 @@
-const API_BASE = "http://localhost:18080";
+const API_BASE = "http://127.0.0.1:18080";
 
-async function apiGet(path) {
-  const res = await fetch(`${API_BASE}${path}`);
+async function apiGet(path, params = {}) {
+  const query = new URLSearchParams(params).toString();
+  const url = `${API_BASE}${path}?${query}`;
+
+  const res = await fetch(url);
   if (!res.ok) {
-    const text = await res.text();
-    throw new Error(text || "APIエラー");
+    const data = await res.json();
+    throw new Error(data.detail || "APIエラー");
   }
   return res.json();
 }
diff --git a/frontend/js/journal.js b/frontend/js/journal.js
new file mode 100644
index 0000000..b5e2583
--- /dev/null
+++ b/frontend/js/journal.js
@@ -0,0 +1,65 @@
+function addLine() {
+  const tbody = document.querySelector("#lines-table tbody");
+
+  const tr = document.createElement("tr");
+  tr.innerHTML = `
+    <td><input type="number" class="account-id" /></td>
+    <td><input type="number" class="debit" value="0" /></td>
+    <td><input type="number" class="credit" value="0" /></td>
+    <td><button onclick="this.closest('tr').remove()">削除</button></td>
+  `;
+
+  tbody.appendChild(tr);
+}
+
+async function submitJournal() {
+  const date = document.getElementById("journal-date").value;
+  const desc = document.getElementById("description").value;
+
+  if (!date) {
+    alert("日付を入力してください");
+    return;
+  }
+
+  const lines = [];
+  document.querySelectorAll("#lines-table tbody tr").forEach((tr) => {
+    const accountId = tr.querySelector(".account-id").value;
+    const debit = tr.querySelector(".debit").value || 0;
+    const credit = tr.querySelector(".credit").value || 0;
+
+    if (!accountId) return;
+
+    lines.push({
+      account_id: Number(accountId),
+      debit: Number(debit),
+      credit: Number(credit),
+    });
+  });
+
+  if (lines.length < 2) {
+    alert("仕訳明細は2行以上必要です");
+    return;
+  }
+
+  try {
+    await fetch("http://127.0.0.1:18080/journals", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        journal_date: date,
+        description: desc,
+        lines: lines,
+      }),
+    }).then(async (res) => {
+      if (!res.ok) {
+        const data = await res.json();
+        throw new Error(data.detail || "登録失敗");
+      }
+    });
+
+    alert("仕訳を登録しました");
+    location.href = "index.html";
+  } catch (e) {
+    alert(e.message);
+  }
+}
diff --git a/frontend/js/ledger.js b/frontend/js/ledger.js
new file mode 100644
index 0000000..a91be7c
--- /dev/null
+++ b/frontend/js/ledger.js
@@ -0,0 +1,37 @@
+async function loadLedger() {
+  const params = new URLSearchParams(location.search);
+  const accountId = params.get("account_id");
+  const from = params.get("from");
+  const to = params.get("to");
+
+  try {
+    const data = await apiGet("/general-ledger", {
+      account_id: accountId,
+      date_from: from,
+      date_to: to,
+    });
+
+    document.getElementById(
+      "account-title"
+    ).innerText = `${data.account.account_code} ${data.account.account_name}`;
+
+    const tbody = document.getElementById("ledger-body");
+    tbody.innerHTML = "";
+
+    data.lines.forEach((line) => {
+      const tr = document.createElement("tr");
+      tr.innerHTML = `
+        <td>${line.journal_date}</td>
+        <td>${line.description}</td>
+        <td>${line.debit}</td>
+        <td>${line.credit}</td>
+        <td>${line.balance}</td>
+      `;
+      tbody.appendChild(tr);
+    });
+  } catch (e) {
+    alert(e.message);
+  }
+}
+
+loadLedger();
diff --git a/frontend/js/opening_balance.js b/frontend/js/opening_balance.js
new file mode 100644
index 0000000..4c156b3
--- /dev/null
+++ b/frontend/js/opening_balance.js
@@ -0,0 +1,152 @@
+let accounts = [];
+let retainedEarnings = null;
+let isLocked = false;
+
+function formatNumber(n) {
+  return Number(n || 0).toLocaleString();
+}
+
+function recalcTotals() {
+  let debit = 0;
+  let credit = 0;
+
+  // 先算：不含繰越利益
+  accounts.forEach((a) => {
+    if (a.account_name === "繰越利益") return;
+    debit += Number(a.opening_debit || 0);
+    credit += Number(a.opening_credit || 0);
+  });
+
+  const diff = debit - credit;
+
+  // 自动计算 繰越利益
+  if (retainedEarnings) {
+    if (diff > 0) {
+      retainedEarnings.opening_debit = 0;
+      retainedEarnings.opening_credit = diff;
+    } else {
+      retainedEarnings.opening_debit = -diff;
+      retainedEarnings.opening_credit = 0;
+    }
+  }
+
+  // 再算一次（包含繰越利益）
+  let finalDebit = 0;
+  let finalCredit = 0;
+
+  accounts.forEach((a) => {
+    finalDebit += Number(a.opening_debit || 0);
+    finalCredit += Number(a.opening_credit || 0);
+  });
+
+  document.getElementById("totalDebit").innerText = formatNumber(finalDebit);
+  document.getElementById("totalCredit").innerText = formatNumber(finalCredit);
+  document.getElementById("diff").innerText = formatNumber(
+    finalDebit - finalCredit
+  );
+}
+
+async function loadOpeningBalances() {
+  const year = document.getElementById("fiscalYear").value;
+
+  const data = await apiGet("/opening-balances", { fiscal_year: year });
+
+  accounts = data;
+  retainedEarnings = accounts.find((a) => a.account_name === "繰越利益");
+
+  const tbody = document.querySelector("#balanceTable tbody");
+  tbody.innerHTML = "";
+
+  GROUPS.forEach((group) => {
+    // 分组标题行
+    const headerTr = document.createElement("tr");
+    headerTr.innerHTML = `
+    <td colspan="4" style="background:#ddd; font-weight:bold;">
+      ${group.label}
+    </td>
+  `;
+    tbody.appendChild(headerTr);
+
+    accounts.forEach((a, i) => {
+      if (a.account_type !== group.key) return;
+
+      const isRetained = a.account_name === "繰越利益";
+      const tr = document.createElement("tr");
+
+      tr.innerHTML = `
+      <td>${a.account_code}</td>
+      <td>${a.account_name}</td>
+      <td>
+        <input type="number" value="${a.opening_debit}"
+          ${isRetained ? "readonly" : ""}
+          onchange="accounts[${i}].opening_debit=this.value; recalcTotals();">
+      </td>
+      <td>
+        <input type="number" value="${a.opening_credit}"
+          ${isRetained ? "readonly" : ""}
+          onchange="accounts[${i}].opening_credit=this.value; recalcTotals();">
+      </td>
+    `;
+
+      tbody.appendChild(tr);
+    });
+  });
+
+  // 年度锁定チェック
+  fetch(
+    `http://127.0.0.1:18080/opening-balances/lock-status?fiscal_year=${year}`
+  )
+    .then((res) => res.json())
+    .then((data) => {
+      isLocked = data.is_locked;
+      document.querySelector(
+        "button[onclick='saveOpeningBalances()']"
+      ).disabled = isLocked;
+      if (isLocked) {
+        alert("この会計年度の期首残高は確定されています。");
+      }
+    });
+
+  recalcTotals();
+}
+
+async function saveOpeningBalances() {
+  if (isLocked) {
+    alert("この会計年度の期首残高は確定されているため、保存できません。");
+    return;
+  }
+  const year = Number(document.getElementById("fiscalYear").value);
+
+  const balances = accounts
+    // ❗ 排除 繰越利益
+    .filter(
+      (a) =>
+        a.account_name !== "繰越利益" &&
+        (Number(a.opening_debit) !== 0 || Number(a.opening_credit) !== 0)
+    )
+    .map((a) => ({
+      account_id: a.account_id,
+      debit: Number(a.opening_debit || 0),
+      credit: Number(a.opening_credit || 0),
+    }));
+
+  try {
+    await fetch("http://127.0.0.1:18080/opening-balances", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        fiscal_year: year,
+        balances: balances,
+      }),
+    }).then(async (res) => {
+      if (!res.ok) {
+        const data = await res.json();
+        throw new Error(data.detail);
+      }
+    });
+
+    alert("期首残高を保存しました");
+  } catch (e) {
+    alert(e.message);
+  }
+}
diff --git a/frontend/js/trial-balance.js b/frontend/js/trial-balance.js
index b785ba8..e93ff4f 100644
--- a/frontend/js/trial-balance.js
+++ b/frontend/js/trial-balance.js
@@ -1,4 +1,4 @@
-document.getElementById("load").onclick = async () => {
+async function loadTrialBalance() {
   const from = document.getElementById("from").value;
   const to = document.getElementById("to").value;
 
@@ -8,22 +8,33 @@ document.getElementById("load").onclick = async () => {
   }
 
   try {
-    const data = await apiGet(`/trial-balance?date_from=${from}&date_to=${to}`);
-    const tbody = document.getElementById("tb-body");
+    const data = await apiGet("/trial-balance", {
+      date_from: from,
+      date_to: to,
+    });
+
+    const tbody = document.querySelector("#trial-table tbody");
     tbody.innerHTML = "";
 
-    data.accounts.forEach((a) => {
+    data.accounts.forEach((acc) => {
       const tr = document.createElement("tr");
+
       tr.innerHTML = `
-        <td>${a.account_name}</td>
-        <td style="text-align:right">${a.opening_balance}</td>
-        <td style="text-align:right">${a.debit}</td>
-        <td style="text-align:right">${a.credit}</td>
-        <td style="text-align:right">${a.closing_balance}</td>
+        <td>${acc.account_code}</td>
+        <td>
+          <a href="ledger.html?account_id=${acc.account_id}&from=${from}&to=${to}">
+            ${acc.account_name}
+          </a>
+        </td>
+        <td>${acc.opening_balance}</td>
+        <td>${acc.debit}</td>
+        <td>${acc.credit}</td>
+        <td>${acc.closing_balance}</td>
       `;
+
       tbody.appendChild(tr);
     });
   } catch (e) {
     alert(e.message);
   }
-};
+}
diff --git a/frontend/ledger.html b/frontend/ledger.html
new file mode 100644
index 0000000..2d4a4ed
--- /dev/null
+++ b/frontend/ledger.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html lang="ja">
+  <head>
+    <meta charset="UTF-8" />
+    <title>元帳</title>
+    <link rel="stylesheet" href="css/style.css" />
+  </head>
+  <body>
+    <h1 id="account-title">元帳</h1>
+
+    <table>
+      <thead>
+        <tr>
+          <th>日付</th>
+          <th>摘要</th>
+          <th>借方</th>
+          <th>贷方</th>
+          <th>残高</th>
+        </tr>
+      </thead>
+      <tbody id="ledger-body"></tbody>
+    </table>
+
+    <a href="index.html">← 試算表へ戻る</a>
+
+    <script src="js/api.js"></script>
+    <script src="js/ledger.js"></script>
+  </body>
+</html>
diff --git a/frontend/opening_balance.html b/frontend/opening_balance.html
new file mode 100644
index 0000000..bc95359
--- /dev/null
+++ b/frontend/opening_balance.html
@@ -0,0 +1,48 @@
+<!DOCTYPE html>
+<html lang="ja">
+  <head>
+    <meta charset="UTF-8" />
+    <title>期首残高入力</title>
+    <link rel="stylesheet" href="css/style.css" />
+  </head>
+  <body>
+    <h1>期首残高入力</h1>
+
+    <label>
+      会計年度：
+      <input type="number" id="fiscalYear" value="2025" />
+    </label>
+    <button onclick="loadOpeningBalances()">読込</button>
+
+    <br /><br />
+
+    <table id="balanceTable">
+      <thead>
+        <tr>
+          <th>科目コード</th>
+          <th>科目名</th>
+          <th>借方期首</th>
+          <th>贷方期首</th>
+        </tr>
+      </thead>
+      <tbody></tbody>
+    </table>
+
+    <br />
+
+    <div>
+      <strong>借方合計：</strong><span id="totalDebit">0</span><br />
+      <strong>贷方合計：</strong><span id="totalCredit">0</span><br />
+      <strong>差額：</strong><span id="diff">0</span>
+    </div>
+
+    <br />
+
+    <button onclick="saveOpeningBalances()">保存</button>
+    <a href="index.html">← 戻る</a>
+
+    <script src="js/api.js"></script>
+    <script src="js/opening_balance.js"></script>
+  </body>
+</html>
+s
diff --git a/メモ.txt b/メモ.txt
index 91396c5..92f5a48 100644
--- a/メモ.txt
+++ b/メモ.txt
@@ -59,9 +59,19 @@ cd C:\workspace\njts-accounting-core\backend
 
 python -m venv .venv
 
+C:\workspace\njts-accounting-core\backend\.venv\pyvenv.cfg
+home = C:\Users\zxh_y\AppData\Local\Programs\Python\Python312
+include-system-site-packages = false
+version = 3.12.9
+executable = C:\Users\zxh_y\AppData\Local\Programs\Python\Python312\python.exe
+command = C:\Users\zxh_y\AppData\Local\Programs\Python\Python312\python.exe -m venv C:\workspace\njts-accounting-core\backend\.venv
+
+
 cd C:\workspace\njts-accounting-core\backend
 .venv\Scripts\activate
+uvicorn app.main:app --reload --host 127.0.0.1 --port 18080
 
+http://localhost:18080/docs
 
 backend\requirements.txt
 ーーーーーーーーーーーーー
@@ -91,4 +101,7 @@ def root():
 
 
 
-pip install psycopg[binary]==3.2.3
\ No newline at end of file
+pip install psycopg[binary]==3.2.3
+
+
+ C:\workspace\njts-accounting-core\backend uvicorn app.main:app --reload --host 127.0.0.1 --port 18080
\ No newline at end of file