diff --git a/backend/app/main.py b/backend/app/main.py
index 6ecace0..a782fdb 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -61,7 +61,8 @@ 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)
 
-
+from app.routers import journal_entries
+app.include_router(journal_entries.router)
 
 
 
diff --git a/backend/app/modules/journal_entry.py b/backend/app/modules/journal_entry.py
new file mode 100644
index 0000000..b740a66
--- /dev/null
+++ b/backend/app/modules/journal_entry.py
@@ -0,0 +1,16 @@
+from pydantic import BaseModel
+from typing import List
+from decimal import Decimal
+from datetime import date
+
+
+class JournalLine(BaseModel):
+    account_id: int
+    debit: Decimal = Decimal("0")
+    credit: Decimal = Decimal("0")
+
+
+class JournalEntryRequest(BaseModel):
+    entry_date: date
+    description: str
+    lines: List[JournalLine]
diff --git a/backend/app/modules/opening_balances/router.py b/backend/app/modules/opening_balances/router.py
index 1103c29..303ae6a 100644
--- a/backend/app/modules/opening_balances/router.py
+++ b/backend/app/modules/opening_balances/router.py
@@ -1,7 +1,7 @@
 from fastapi import APIRouter, HTTPException, Query
-from pydantic import BaseModel
-from typing import List
-from decimal import Decimal
+from pydantic import BaseModel, field_validator
+from typing import List, Optional, Tuple
+from decimal import Decimal, InvalidOperation
 
 from app.core.database import get_connection
 
@@ -15,13 +15,33 @@ class OpeningBalanceItem(BaseModel):
     debit: Decimal = Decimal("0")
     credit: Decimal = Decimal("0")
 
+    @field_validator("debit", "credit", mode="before")
+    @classmethod
+    def to_decimal(cls, v):
+        try:
+            d = Decimal(str(v))
+        except InvalidOperation:
+            raise ValueError("金額は数値で入力してください")
+        if d < 0:
+            raise ValueError("金額は0以上で入力してください")
+        return d
+
+    @field_validator("credit")
+    @classmethod
+    def exclusive_debit_credit(cls, v, info):
+        # 同時に > 0 は不可（0/0 は許容：行スキップ用）
+        debit = info.data.get("debit", Decimal("0"))
+        if v > 0 and Decimal(debit) > 0:
+            raise ValueError("借方と貸方を同時に入力しないでください")
+        return v
+
 
 class OpeningBalanceRequest(BaseModel):
     fiscal_year: int
     balances: List[OpeningBalanceItem]
 
 
-# ---------- GET：期首残高取得 ----------
+# ---------- GET：期首残高取得（BS のみ） ----------
 
 @router.get("", summary="期首残高取得")
 def get_opening_balances(
@@ -41,68 +61,142 @@ def get_opening_balances(
               ON o.account_id = a.account_id
              AND o.fiscal_year = %s
             WHERE a.is_active = true
+              AND a.account_type IN ('asset','liability','equity')
             ORDER BY a.account_code
         """, (fiscal_year,))
         return cur.fetchall()
 
 
-# ---------- POST：期首残高保存 ----------
+# ---------- 内部 util：繰越利益（剰余金）アカウント検索 ----------
+
+def _find_retained_earnings(cur) -> Optional[Tuple[int, str]]:
+    """
+    可能な名称で繰越利益（剰余金）科目を探す。
+    優先：'繰越利益剰余金' → '繰越利益'
+    戻り値： (account_id, account_name) or None
+    """
+    cur.execute("""
+        SELECT account_id, account_name
+          FROM accounts
+         WHERE is_active = true
+           AND account_type = 'equity'
+           AND account_name IN ('繰越利益剰余金','繰越利益')
+         ORDER BY CASE account_name
+                    WHEN '繰越利益剰余金' THEN 1
+                    WHEN '繰越利益'       THEN 2
+                    ELSE 99
+                  END
+         LIMIT 1
+    """)
+    row = cur.fetchone()
+    return (row["account_id"], row["account_name"]) if row else None
+
+
+# ---------- POST：期首残高保存（BSのみ・繰越利益は自動計算） ----------
 
 @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）
+        # 年度ロック
         cur.execute("""
-            DELETE FROM opening_balances
+            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。")
+
+        # 全 BS 科目取得（存在性/種別チェック用）
+        cur.execute("""
+            SELECT account_id, account_type, account_name
+              FROM accounts
+             WHERE is_active = true
+        """)
+        acc_map = {r["account_id"]: (r["account_type"], r["account_name"]) for r in cur.fetchall()}
+
+        # 入力の整形：BSのみ採用・繰越利益は無視（後で自動作成）
+        bs_items: List[OpeningBalanceItem] = []
+        total_debit = Decimal("0")
+        total_credit = Decimal("0")
 
-        # 再登録
         for b in req.balances:
+            # 科目存在
+            if b.account_id not in acc_map:
+                raise HTTPException(status_code=400, detail=f"存在しない科目IDです：{b.account_id}")
+
+            acc_type, acc_name = acc_map[b.account_id]
+
+            # 繰越利益（剰余金）は前端から送られても無視（自動計算対象）
+            if acc_name in ("繰越利益剰余金", "繰越利益"):
+                continue
+
+            # BS 以外は不可
+            if acc_type not in ("asset", "liability", "equity"):
+                raise HTTPException(status_code=400, detail=f"BS科目のみ設定可能です（{acc_name}）")
+
+            # 0/0 はスキップ
             if b.debit == 0 and b.credit == 0:
                 continue
 
+            # 集計（繰越利益を除く）
+            total_debit += b.debit
+            total_credit += b.credit
+            bs_items.append(b)
+
+        # 繰越利益（剰余金）を自動計算
+        diff = total_debit - total_credit  # 借方合計 − 貸方合計
+        re_account = _find_retained_earnings(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：BS各行
+        for b in bs_items:
             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
-            ))
+                VALUES (%s, %s, %s, %s)
+            """, (req.fiscal_year, b.account_id, b.debit, b.credit))
+
+        # 自動：繰越利益（剰余金）
+        re_inserted = None
+        if re_account:
+            re_id, re_name = re_account
+            if diff > 0:
+                # 借方が大 → その差額を「繰越利益（剰余金）の貸方」
+                cur.execute("""
+                    INSERT INTO opening_balances (fiscal_year, account_id, opening_debit, opening_credit)
+                    VALUES (%s, %s, %s, %s)
+                """, (req.fiscal_year, re_id, Decimal("0"), diff))
+                re_inserted = {"account_id": re_id, "name": re_name, "debit": "0", "credit": str(diff)}
+            elif diff < 0:
+                # 贷方が大 → その差額を「繰越利益（剰余金）の借方」
+                cur.execute("""
+                    INSERT INTO opening_balances (fiscal_year, account_id, opening_debit, opening_credit)
+                    VALUES (%s, %s, %s, %s)
+                """, (req.fiscal_year, re_id, -diff, Decimal("0")))
+                re_inserted = {"account_id": re_id, "name": re_name, "debit": str(-diff), "credit": "0"}
+            else:
+                # 完全一致 → 追加不要
+                pass
+        else:
+            # 繰越利益科目が登録されていない場合：差額が 0 でないなら警告
+            if diff != 0:
+                raise HTTPException(
+                    status_code=400,
+                    detail="差額がありますが『繰越利益（剰余金）』科目が見つかりません。先に科目マスタを登録してください。"
+                )
 
         conn.commit()
 
-    return {"message": "期首残高を保存しました。"}
+    return {
+        "message": "期首残高を保存しました。",
+        "totals": {
+            "debit": str(total_debit),
+            "credit": str(total_credit),
+            "diff_before_retained": str(diff)
+        },
+        "retained_earnings_auto": re_inserted
+    }
diff --git a/backend/app/routers/__init__.py b/backend/app/routers/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/backend/app/routers/accounts.py b/backend/app/routers/accounts.py
new file mode 100644
index 0000000..e69de29
diff --git a/backend/app/routers/journal_entries.py b/backend/app/routers/journal_entries.py
new file mode 100644
index 0000000..826056e
--- /dev/null
+++ b/backend/app/routers/journal_entries.py
@@ -0,0 +1,232 @@
+from fastapi import APIRouter, HTTPException, Query
+from typing import Optional
+from decimal import Decimal
+from datetime import date
+
+from app.core.database import get_connection
+from app.models.journal_entry import JournalEntryRequest
+
+router = APIRouter(prefix="/journal-entries", tags=["仕訳"])
+
+
+# -------------------------------------------------
+# 仕訳登録
+# -------------------------------------------------
+@router.post("", summary="仕訳登録")
+def create_journal_entry(req: JournalEntryRequest):
+
+    if len(req.lines) < 2:
+        raise HTTPException(status_code=400, detail="仕訳行は2行以上必要です")
+
+    if req.entry_date < date(2025, 6, 1):
+        raise HTTPException(status_code=400, detail="仕訳日は2025-06-01以降である必要があります")
+
+    debit_total = Decimal("0")
+    credit_total = Decimal("0")
+
+    for line in req.lines:
+        if line.debit < 0 or line.credit < 0:
+            raise HTTPException(status_code=400, detail="金額は正数で入力してください")
+
+        if line.debit > 0 and line.credit > 0:
+            raise HTTPException(status_code=400, detail="同一行で借方・貸方の同時入力は不可です")
+
+        debit_total += line.debit
+        credit_total += line.credit
+
+    if debit_total != credit_total:
+        raise HTTPException(
+            status_code=400,
+            detail=f"借方合計({debit_total})と貸方合計({credit_total})が一致しません"
+        )
+
+    with get_connection() as conn, conn.cursor() as cur:
+
+        # 期首ロック確認
+        cur.execute("""
+            SELECT is_locked
+            FROM opening_balance_locks
+            WHERE fiscal_year = 2025
+        """)
+        row = cur.fetchone()
+        if not row or not row[0]:
+            raise HTTPException(status_code=400, detail="期首残高が確定（lock）されていません")
+
+        # ヘッダ登録
+        cur.execute("""
+            INSERT INTO journal_entries (entry_date, description)
+            VALUES (%s, %s)
+            RETURNING journal_entry_id
+        """, (req.entry_date, req.description))
+        journal_entry_id = cur.fetchone()[0]
+
+        # 明細登録
+        for line in req.lines:
+            cur.execute("""
+                INSERT INTO journal_lines
+                (journal_entry_id, account_id, debit, credit)
+                VALUES (%s, %s, %s, %s)
+            """, (
+                journal_entry_id,
+                line.account_id,
+                line.debit,
+                line.credit
+            ))
+
+    return {
+        "message": "仕訳を登録しました",
+        "journal_entry_id": journal_entry_id
+    }
+
+
+# -------------------------------------------------
+# 仕訳一覧取得
+# -------------------------------------------------
+@router.get("", summary="仕訳一覧取得")
+def list_journal_entries(
+    from_date: Optional[str] = Query(None),
+    to_date: Optional[str] = Query(None),
+    keyword: Optional[str] = Query(None)
+):
+    sql = """
+      SELECT
+        je.journal_entry_id,
+        je.entry_date,
+        je.description,
+        SUM(jl.debit)  AS debit_total,
+        SUM(jl.credit) AS credit_total
+      FROM journal_entries je
+      JOIN journal_lines jl
+        ON jl.journal_entry_id = je.journal_entry_id
+      WHERE 1=1
+    """
+    params = []
+
+    if from_date:
+        sql += " AND je.entry_date >= %s"
+        params.append(from_date)
+    if to_date:
+        sql += " AND je.entry_date <= %s"
+        params.append(to_date)
+    if keyword:
+        sql += " AND je.description ILIKE %s"
+        params.append(f"%{keyword}%")
+
+    sql += """
+      GROUP BY je.journal_entry_id, je.entry_date, je.description
+      ORDER BY je.entry_date DESC, je.journal_entry_id DESC
+    """
+
+    with get_connection() as conn, conn.cursor() as cur:
+        cur.execute(sql, params)
+        rows = cur.fetchall()
+
+    return [
+        {
+            "journal_entry_id": r[0],
+            "entry_date": r[1],
+            "description": r[2],
+            "debit_total": r[3],
+            "credit_total": r[4],
+        }
+        for r in rows
+    ]
+
+
+# -------------------------------------------------
+# 仕訳明細取得
+# -------------------------------------------------
+@router.get("/{journal_entry_id}", summary="仕訳明細取得")
+def get_journal_entry(journal_entry_id: int):
+    with get_connection() as conn, conn.cursor() as cur:
+
+        cur.execute("""
+          SELECT entry_date, description
+          FROM journal_entries
+          WHERE journal_entry_id = %s
+        """, (journal_entry_id,))
+        header = cur.fetchone()
+        if not header:
+            raise HTTPException(status_code=404, detail="仕訳が存在しません")
+
+        cur.execute("""
+          SELECT
+            jl.account_id,
+            a.account_code,
+            a.account_name,
+            jl.debit,
+            jl.credit
+          FROM journal_lines jl
+          JOIN accounts a ON a.account_id = jl.account_id
+          WHERE jl.journal_entry_id = %s
+        """, (journal_entry_id,))
+        lines = cur.fetchall()
+
+    return {
+        "entry_date": header[0],
+        "description": header[1],
+        "lines": [
+            {
+                "account_id": l[0],
+                "account_code": l[1],
+                "account_name": l[2],
+                "debit": l[3],
+                "credit": l[4]
+            } for l in lines
+        ]
+    }
+
+
+# -------------------------------------------------
+# 逆仕訳生成（修正仕訳）
+# -------------------------------------------------
+@router.post("/{journal_entry_id}/reverse", summary="逆仕訳生成")
+def reverse_journal_entry(journal_entry_id: int):
+    with get_connection() as conn, conn.cursor() as cur:
+
+        # 元仕訳取得
+        cur.execute("""
+            SELECT entry_date, description
+            FROM journal_entries
+            WHERE journal_entry_id = %s
+        """, (journal_entry_id,))
+        header = cur.fetchone()
+        if not header:
+            raise HTTPException(status_code=404, detail="仕訳が存在しません")
+
+        entry_date, description = header
+
+        cur.execute("""
+            SELECT account_id, debit, credit
+            FROM journal_lines
+            WHERE journal_entry_id = %s
+        """, (journal_entry_id,))
+        lines = cur.fetchall()
+        if not lines:
+            raise HTTPException(status_code=400, detail="仕訳明細が存在しません")
+
+        # 逆仕訳ヘッダ
+        cur.execute("""
+            INSERT INTO journal_entries (entry_date, description)
+            VALUES (%s, %s)
+            RETURNING journal_entry_id
+        """, (entry_date, f"【修正】{description}"))
+        new_entry_id = cur.fetchone()[0]
+
+        # 逆仕訳明細（借贷反転）
+        for account_id, debit, credit in lines:
+            cur.execute("""
+                INSERT INTO journal_lines
+                (journal_entry_id, account_id, debit, credit)
+                VALUES (%s, %s, %s, %s)
+            """, (
+                new_entry_id,
+                account_id,
+                credit,
+                debit
+            ))
+
+    return {
+        "message": "逆仕訳を作成しました",
+        "reversed_journal_entry_id": new_entry_id
+    }
diff --git a/backend/app/routers/opening_balances.py b/backend/app/routers/opening_balances.py
new file mode 100644
index 0000000..e69de29
diff --git a/backend/requirements.txt b/backend/requirements.txt
index ad4ca54..1a34c78 100644
Binary files a/backend/requirements.txt and b/backend/requirements.txt differ
diff --git a/backend/sql/001_accounts_bs_master.sql b/backend/sql/001_accounts_bs_master.sql
new file mode 100644
index 0000000..a413e4a
--- /dev/null
+++ b/backend/sql/001_accounts_bs_master.sql
@@ -0,0 +1,41 @@
+-- =========================
+-- BS 科目マスタ（3桁コード）
+-- =========================
+
+-- 資産
+INSERT INTO accounts (account_code, account_name, account_type) VALUES
+('101', '現金', 'asset'),
+('102', '普通預金', 'asset'),
+('103', '当座預金', 'asset'),
+('104', '定期預金', 'asset'),
+('201', '売掛金', 'asset'),
+('202', '未収入金', 'asset'),
+('203', '仮払金', 'asset'),
+('204', '前払費用', 'asset'),
+('205', '立替金', 'asset'),
+('301', '有価証券', 'asset'),
+('401', '建物', 'asset'),
+('402', '建物附属設備', 'asset'),
+('403', '構築物', 'asset'),
+('404', '機械装置', 'asset'),
+('405', '車両運搬具', 'asset'),
+('406', '工具器具備品', 'asset'),
+('407', '土地', 'asset'),
+('408', 'ソフトウェア', 'asset');
+
+-- 負債
+INSERT INTO accounts (account_code, account_name, account_type) VALUES
+('501', '買掛金', 'liability'),
+('502', '未払金', 'liability'),
+('503', '未払費用', 'liability'),
+('504', '未払法人税等', 'liability'),
+('505', '未払消費税等', 'liability'),
+('506', '預り金', 'liability'),
+('507', '前受金', 'liability'),
+('508', '短期借入金', 'liability'),
+('509', '長期借入金', 'liability');
+
+-- 純資産
+INSERT INTO accounts (account_code, account_name, account_type) VALUES
+('601', '資本金', 'equity'),
+('602', '繰越利益剰余金', 'equity');
diff --git a/frontend/journal-entry.html b/frontend/journal-entry.html
new file mode 100644
index 0000000..c56a8c0
--- /dev/null
+++ b/frontend/journal-entry.html
@@ -0,0 +1,324 @@
+<!DOCTYPE html>
+<html lang="ja">
+<head>
+  <meta charset="UTF-8" />
+  <title>仕訳入力（複数行・消費税自動）</title>
+  <style>
+    body { font-family: sans-serif; margin: 24px; }
+    table { border-collapse: collapse; width: 100%; margin-top: 12px; }
+    th, td { border: 1px solid #ccc; padding: 6px; text-align: center; }
+    th { background: #f5f5f5; }
+    input, select, button { padding: 6px; }
+    .right { text-align: right; }
+    .error { color: #c00; margin-top: 8px; }
+    .ok { color: #090; margin-top: 8px; }
+    .row { display: flex; gap: 12px; align-items: center; margin: 8px 0; }
+    .row > * { flex: 1; }
+  </style>
+</head>
+<body>
+
+<h2><div class="row">
+  <div>
+    <label>消費税 端数処理</label>
+    <select id="roundingMode">
+      <option value="round">四捨五入</option>
+      <option value="floor">切捨て</option>
+      <option value="ceil">切上げ</option>
+    </select>
+  </div>
+</div></h2>
+
+<div class="row">
+  <div>
+    <label>仕訳日</label>
+    <input type="date" id="entryDate" />
+  </div>
+  <div style="flex:2">
+    <label>摘要</label>
+    <input type="text" id="description" placeholder="例：売上計上／経費支払" style="width:100%" />
+  </div>
+</div>
+
+<div class="row">
+  <div>
+    <label>仮払消費税等 勘定</label>
+    <select id="taxDebitAccount"></select>
+  </div>
+  <div>
+    <label>仮受消費税等 勘定</label>
+    <select id="taxCreditAccount"></select>
+  </div>
+</div>
+
+<table id="linesTable">
+  <thead>
+    <tr>
+      <th>科目</th>
+      <th>借方</th>
+      <th>貸方</th>
+      <th>税区分</th>
+      <th>税方向</th>
+      <th>操作</th>
+    </tr>
+  </thead>
+  <tbody></tbody>
+  <tfoot>
+    <tr>
+      <th>合計</th>
+      <th id="debitTotal" class="right">0</th>
+      <th id="creditTotal" class="right">0</th>
+      <th colspan="3"></th>
+    </tr>
+  </tfoot>
+</table>
+
+<button onclick="addRow()">＋ 行追加</button>
+<button onclick="submitEntry()">登録</button>
+
+<div id="result"></div>
+
+<script>
+const API_BASE = "http://127.0.0.1:18080";
+let accounts = [];
+
+const TAX_OPTIONS = [
+  { value: "none", label: "非課税" },
+  { value: "10-excl", label: "10%（税抜）" },
+  { value: "10-incl", label: "10%（税込）" },
+  { value: "8-excl",  label: "8%（税抜）"  },
+  { value: "8-incl",  label: "8%（税込）"  }
+];
+
+const TAX_DIRECTIONS = [
+  { value: "karibarai", label: "仮払（仕入・経費側）" },
+  { value: "kariuke",   label: "仮受（売上側）" }
+];
+
+// ------------------------
+// 初期化
+// ------------------------
+async function init() {
+  const res = await fetch(`${API_BASE}/accounts`);
+  accounts = await res.json();
+
+  // 税勘定候補を抽出
+  const taxDebitSel  = document.getElementById("taxDebitAccount");
+  const taxCreditSel = document.getElementById("taxCreditAccount");
+
+  const taxDebitCandidates  = accounts.filter(a => a.account_name.includes("仮払消費税"));
+  const taxCreditCandidates = accounts.filter(a => a.account_name.includes("仮受消費税"));
+
+  // 仮払
+  fillSelect(taxDebitSel, taxDebitCandidates.length ? taxDebitCandidates : accounts);
+  // 仮受
+  fillSelect(taxCreditSel, taxCreditCandidates.length ? taxCreditCandidates : accounts);
+
+  addRow();
+  addRow();
+  recalc();
+}
+
+function fillSelect(sel, list) {
+  sel.innerHTML = "";
+  list.forEach(a => {
+    const opt = document.createElement("option");
+    opt.value = a.account_id;
+    opt.textContent = `${a.account_code} ${a.account_name}`;
+    sel.appendChild(opt);
+  });
+}
+
+// ------------------------
+// 行追加・削除
+// ------------------------
+function addRow() {
+  const tbody = document.querySelector("#linesTable tbody");
+  const tr = document.createElement("tr");
+
+  tr.innerHTML = `
+    <td>
+      <select class="account">
+        ${accounts.map(a =>
+          `<option value="${a.account_id}">${a.account_code} ${a.account_name}</option>`
+        ).join("")}
+      </select>
+    </td>
+    <td><input type="number" min="0" class="debit"  oninput="onDebitInput(this)" /></td>
+    <td><input type="number" min="0" class="credit" oninput="onCreditInput(this)" /></td>
+    <td>
+      <select class="tax">
+        ${TAX_OPTIONS.map(t => `<option value="${t.value}">${t.label}</option>`).join("")}
+      </select>
+    </td>
+    <td>
+      <select class="taxdir">
+        ${TAX_DIRECTIONS.map(t => `<option value="${t.value}">${t.label}</option>`).join("")}
+      </select>
+    </td>
+    <td><button onclick="removeRow(this)">削除</button></td>
+  `;
+  tbody.appendChild(tr);
+}
+
+function removeRow(btn) {
+  btn.closest("tr").remove();
+  recalc();
+}
+
+function onDebitInput(input) {
+  const credit = input.closest("tr").querySelector(".credit");
+  if (input.value) credit.value = "";
+  recalc();
+}
+
+function onCreditInput(input) {
+  const debit = input.closest("tr").querySelector(".debit");
+  if (input.value) debit.value = "";
+  recalc();
+}
+
+// ------------------------
+// 合計再計算（税は送信時に展開するので、ここは本体行のみ）
+// ------------------------
+function recalc() {
+  let debitTotal = 0;
+  let creditTotal = 0;
+  document.querySelectorAll("#linesTable tbody tr").forEach(tr => {
+    const d = Number(tr.querySelector(".debit").value || 0);
+    const c = Number(tr.querySelector(".credit").value || 0);
+    debitTotal  += d;
+    creditTotal += c;
+  });
+  document.getElementById("debitTotal").textContent  = debitTotal.toLocaleString();
+  document.getElementById("creditTotal").textContent = creditTotal.toLocaleString();
+}
+
+// ------------------------
+// 税計算（四捨五入）
+// ------------------------
+function calcTaxSplit(amount, rate, inclusive) {
+  if (!rate) return { base: amount, tax: 0 };
+
+  if (!inclusive) {
+    // 税抜：amount = 本体
+    const tax = applyRounding(amount * rate);
+    return { base: amount, tax };
+  } else {
+    // 税込：amount = 総額
+    const base = applyRounding(amount / (1 + rate));
+    const tax  = amount - base; // 差額は必ず一致させる
+    return { base, tax };
+  }
+}
+
+function parseTaxOption(opt) {
+  if (opt === "none") return { rate: 0, inclusive: false };
+  const [rateStr, mode] = opt.split("-");
+  const rate = rateStr === "10" ? 0.10 : 0.08;
+  return { rate, inclusive: mode === "incl" };
+}
+
+// ------------------------
+// 送信（税行を自動付与）
+// ------------------------
+async function submitEntry() {
+  const result = document.getElementById("result");
+  result.textContent = "";
+  result.className = "";
+
+  const entryDate = document.getElementById("entryDate").value;
+  const desc = document.getElementById("description").value;
+  if (!entryDate) return showError("仕訳日を入力してください");
+  if (!desc) return showError("摘要を入力してください");
+
+  const taxDebitAccountId  = Number(document.getElementById("taxDebitAccount").value);
+  const taxCreditAccountId = Number(document.getElementById("taxCreditAccount").value);
+
+  const baseLines = [];
+  const taxLines  = [];
+
+  document.querySelectorAll("#linesTable tbody tr").forEach(tr => {
+    const accountId = Number(tr.querySelector(".account").value);
+    const debit  = Number(tr.querySelector(".debit").value || 0);
+    const credit = Number(tr.querySelector(".credit").value || 0);
+    const taxOpt = tr.querySelector(".tax").value;
+    const taxDir = tr.querySelector(".taxdir").value;
+
+    // 空行は無視
+    if (debit === 0 && credit === 0) return;
+
+    const { rate, inclusive } = parseTaxOption(taxOpt);
+
+    if (debit > 0) {
+      const { base, tax } = calcTaxSplit(debit, rate, inclusive);
+      baseLines.push({ account_id: accountId, debit: base, credit: 0 });
+      if (tax > 0) {
+        if (taxDir === "karibarai") {
+          taxLines.push({ account_id: taxDebitAccountId,  debit: tax, credit: 0 });
+        } else {
+          taxLines.push({ account_id: taxCreditAccountId, debit: 0,   credit: tax });
+        }
+      }
+    } else {
+      const { base, tax } = calcTaxSplit(credit, rate, inclusive);
+      baseLines.push({ account_id: accountId, debit: 0, credit: base });
+      if (tax > 0) {
+        if (taxDir === "karibarai") {
+          taxLines.push({ account_id: taxDebitAccountId,  debit: tax, credit: 0 });
+        } else {
+          taxLines.push({ account_id: taxCreditAccountId, debit: 0,   credit: tax });
+        }
+      }
+    }
+  });
+
+  const lines = [...baseLines, ...taxLines];
+
+  if (lines.length < 2)
+    return showError("仕訳行は2行以上必要です");
+
+  // 借貸チェック（送信前に最終確認）
+  const tot = lines.reduce((s, l) => {
+    s.debit  += Number(l.debit  || 0);
+    s.credit += Number(l.credit || 0);
+    return s;
+  }, {debit:0, credit:0});
+
+  if (tot.debit !== tot.credit)
+    return showError(`借方合計(${tot.debit})と貸方合計(${tot.credit})が一致していません`);
+
+  const payload = { entry_date: entryDate, description: desc, lines };
+
+  try {
+    const res = await fetch(`${API_BASE}/journal-entries`, {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify(payload)
+    });
+    const data = await res.json();
+    if (!res.ok) return showError(data.detail || "登録失敗");
+    showOk(`登録完了（ID: ${data.journal_entry_id}）`);
+  } catch {
+    showError("通信エラー");
+  }
+}
+
+function showError(msg) {
+  const r = document.getElementById("result");
+  r.textContent = msg;
+  r.className = "error";
+}
+function showOk(msg) {
+  const r = document.getElementById("result");
+  r.textContent = msg;
+  r.className = "ok";
+}
+
+// 合計の初期表示用
+document.addEventListener("input", () => recalc());
+init();
+</script>
+
+</body>
+</html>
diff --git a/frontend/journal-list.html b/frontend/journal-list.html
new file mode 100644
index 0000000..4898b58
--- /dev/null
+++ b/frontend/journal-list.html
@@ -0,0 +1,97 @@
+<!DOCTYPE html>
+<html lang="ja">
+<head>
+<meta charset="UTF-8">
+<title>仕訳一覧</title>
+<style>
+  body { font-family: sans-serif; margin: 24px; }
+  table { border-collapse: collapse; width: 100%; margin-top: 12px; }
+  th, td { border: 1px solid #ccc; padding: 6px; }
+  th { background: #f5f5f5; }
+</style>
+</head>
+<body>
+
+<h2>仕訳一覧</h2>
+
+<label>期間</label>
+<input type="date" id="fromDate"> ～ <input type="date" id="toDate">
+
+<label>摘要</label>
+<input type="text" id="keyword">
+
+<button onclick="search()">検索</button>
+
+<table>
+  <thead>
+    <tr>
+      <th>日付</th>
+      <th>摘要</th>
+      <th>借方合計</th>
+      <th>贷方合计</th>
+      <th>操作</th>
+    </tr>
+  </thead>
+  <tbody id="list"></tbody>
+</table>
+
+<script>
+const API = "http://127.0.0.1:18080";
+
+async function search() {
+  const from = document.getElementById("fromDate").value;
+  const to   = document.getElementById("toDate").value;
+  const key  = document.getElementById("keyword").value;
+
+  const qs = new URLSearchParams();
+  if (from) qs.append("from_date", from);
+  if (to)   qs.append("to_date", to);
+  if (key)  qs.append("keyword", key);
+
+  const res = await fetch(`${API}/journal-entries?${qs.toString()}`);
+  const data = await res.json();
+
+  const tbody = document.getElementById("list");
+  tbody.innerHTML = "";
+
+  data.forEach(e => {
+    const tr = document.createElement("tr");
+    tr.innerHTML = `
+      <td>${e.entry_date}</td>
+      <td>${e.description}</td>
+      <td style="text-align:right">${e.debit_total.toLocaleString()}</td>
+      <td style="text-align:right">${e.credit_total.toLocaleString()}</td>
+      <td>
+        <button onclick="view(${e.journal_entry_id})">表示</button>
+        <button onclick="reverse(${e.journal_entry_id})">修正</button>
+      </td>
+    `;
+    tbody.appendChild(tr);
+  });
+}
+
+function view(id) {
+  window.open(`journal-view.html?id=${id}`, "_blank");
+}
+
+async function reverse(id) {
+  if (!confirm("この仕訳の逆仕訳を作成します。よろしいですか？")) return;
+
+  const res = await fetch(`${API}/journal-entries/${id}/reverse`, {
+    method: "POST"
+  });
+
+  const data = await res.json();
+
+  if (!res.ok) {
+    alert(data.detail || "逆仕訳の作成に失敗しました");
+    return;
+  }
+
+  alert(`逆仕訳を作成しました（ID: ${data.reversed_journal_entry_id}）`);
+  search();
+}
+</script>
+
+</body>
+</html>