diff --git a/backend/package.json b/backend/package.json
index fa8128c..536889d 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -15,6 +15,7 @@
     "db:migrate:up": "npm run build && node dist/db/migrate-cli.js up",
     "db:migrate:verify": "npm run build && node dist/db/migrate-cli.js verify",
     "db:migrate:down": "npm run build && node dist/db/migrate-cli.js down",
+    "test:mysql:migration": "npm run build && node tests/mysql-migration-roundtrip.test.mjs",
     "test": "npm run build && node tests/backend-contract.test.mjs && node tests/migration-contract.test.mjs && node tests/mysql-pool-contract.test.mjs && node tests/migration-runner.test.mjs && node tests/legacy-money.test.mjs && node tests/legacy-read-repository.test.mjs"
   },
   "dependencies": {
diff --git a/backend/tests/mysql-migration-roundtrip.test.mjs b/backend/tests/mysql-migration-roundtrip.test.mjs
new file mode 100644
index 0000000..e7d2ab9
--- /dev/null
+++ b/backend/tests/mysql-migration-roundtrip.test.mjs
@@ -0,0 +1,100 @@
+import assert from 'node:assert/strict';
+import { loadConfig } from '../dist/config.js';
+import { closeMySqlPool, createMySqlPool } from '../dist/db/mysql.js';
+import {
+  executeMigrationPlan,
+  loadMigrationPlan
+} from '../dist/db/migration-runner.js';
+
+const expectedTables = [
+  'qipai_audit_logs',
+  'qipai_devices',
+  'qipai_legacy_table_mappings',
+  'qipai_members',
+  'qipai_orders',
+  'qipai_payments',
+  'qipai_rooms',
+  'qipai_schema_migrations',
+  'qipai_stores',
+  'qipai_tenants'
+];
+
+async function readCoreTables(pool) {
+  const placeholders = expectedTables.map(() => '?').join(', ');
+  const [rows] = await pool.query(
+    `SELECT table_name AS tableName
+     FROM information_schema.tables
+     WHERE table_schema = DATABASE()
+       AND table_name IN (${placeholders})
+     ORDER BY table_name`,
+    expectedTables
+  );
+  return rows.map((row) => row.tableName);
+}
+
+async function readMigrationVersion(pool) {
+  const [rows] = await pool.query(
+    `SELECT version, name
+     FROM qipai_schema_migrations
+     WHERE version = ?`,
+    ['2026061601']
+  );
+  return rows;
+}
+
+const config = loadConfig();
+assert.equal(config.mysql.passwordConfigured, true, 'Live migration test requires a temporary password.');
+assert.match(
+  config.mysql.database,
+  /^qipai_m01b_test_[a-z0-9_]+$/,
+  'Live migration test refuses to use a non-temporary database.'
+);
+
+const plans = {
+  up: await loadMigrationPlan('up'),
+  verify: await loadMigrationPlan('verify'),
+  down: await loadMigrationPlan('down')
+};
+const pool = createMySqlPool(config);
+
+try {
+  await executeMigrationPlan(pool, plans.up);
+  await executeMigrationPlan(pool, plans.verify);
+  assert.deepEqual(await readCoreTables(pool), expectedTables);
+  assert.deepEqual(await readMigrationVersion(pool), [{
+    version: '2026061601',
+    name: 'm01b_core_schema'
+  }]);
+  console.log('PASS: first up and verify completed.');
+
+  await executeMigrationPlan(pool, plans.down);
+  assert.deepEqual(await readCoreTables(pool), []);
+  console.log('PASS: down removed all M01-B core tables.');
+
+  await executeMigrationPlan(pool, plans.up);
+  await executeMigrationPlan(pool, plans.verify);
+  assert.deepEqual(await readCoreTables(pool), expectedTables);
+  assert.deepEqual(await readMigrationVersion(pool), [{
+    version: '2026061601',
+    name: 'm01b_core_schema'
+  }]);
+  console.log('PASS: second up and verify restored the schema.');
+
+  console.log(JSON.stringify({
+    mysqlHost: config.mysql.host,
+    databaseClass: 'temporary',
+    sequence: ['up', 'verify', 'down', 'up', 'verify'],
+    checksums: {
+      up: plans.up.checksum,
+      verify: plans.verify.checksum,
+      down: plans.down.checksum
+    },
+    statementCounts: {
+      up: plans.up.statements.length,
+      verify: plans.verify.statements.length,
+      down: plans.down.statements.length
+    }
+  }, null, 2));
+} finally {
+  await closeMySqlPool(pool);
+}
diff --git a/scripts/dev/windows/check-backend.ps1 b/scripts/dev/windows/check-backend.ps1
index b6505f3..381cef5 100644
--- a/scripts/dev/windows/check-backend.ps1
+++ b/scripts/dev/windows/check-backend.ps1
@@ -17,7 +17,9 @@ $requiredFiles = @(
   "backend/tests/migration-contract.test.mjs",
   "backend/tests/mysql-pool-contract.test.mjs",
   "backend/tests/migration-runner.test.mjs",
+  "backend/tests/mysql-migration-roundtrip.test.mjs",
   "backend/tests/legacy-read-repository.test.mjs",
+  "scripts/dev/wsl/mysql-migration-roundtrip.sh",
   "database/migrations/2026061601_m01b_core_schema.up.sql",
   "database/migrations/2026061601_m01b_core_schema.down.sql",
   "database/migrations/2026061601_m01b_core_schema.verify.sql",
@@ -31,6 +33,11 @@ foreach ($path in $requiredFiles) {
   }
 }
 
+$packageJson = Get-Content "backend/package.json" -Raw | ConvertFrom-Json
+if (-not $packageJson.scripts.'test:mysql:migration') {
+  throw "backend/package.json is missing test:mysql:migration"
+}
+
 & npm --prefix backend test
 if ($LASTEXITCODE -ne 0) {
   throw "backend contract test failed"
diff --git a/scripts/dev/windows/check-repo-completeness.ps1 b/scripts/dev/windows/check-repo-completeness.ps1
index 5f8dbbb..b11a30d 100644
--- a/scripts/dev/windows/check-repo-completeness.ps1
+++ b/scripts/dev/windows/check-repo-completeness.ps1
@@ -25,6 +25,7 @@ $requiredPaths = @(
   "backend/src/db/mysql.ts",
   "backend/tests/migration-contract.test.mjs",
   "backend/tests/mysql-pool-contract.test.mjs",
+  "backend/tests/mysql-migration-roundtrip.test.mjs",
   "database/migrations/2026061601_m01b_core_schema.up.sql",
   "database/migrations/2026061601_m01b_core_schema.down.sql",
   "database/migrations/2026061601_m01b_core_schema.verify.sql",
@@ -46,6 +47,7 @@ $requiredPaths = @(
   "scripts/dev/wsl/prepare-test-copy.sh",
   "scripts/dev/wsl/verify-linux.sh",
   "scripts/dev/wsl/mqtt-smoke.sh",
+  "scripts/dev/wsl/mysql-migration-roundtrip.sh",
   "scripts/dev/wsl/check-gitea-ssh.sh",
   "scripts/dev/wsl/check-api-domain.sh",
   "scripts/dev/wsl/cleanup-test-copy.sh"
diff --git a/scripts/dev/wsl/mysql-migration-roundtrip.sh b/scripts/dev/wsl/mysql-migration-roundtrip.sh
new file mode 100644
index 0000000..ed7a259
--- /dev/null
+++ b/scripts/dev/wsl/mysql-migration-roundtrip.sh
@@ -0,0 +1,98 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../.." && pwd)"
+case "${repo_root}" in
+  /mnt/*|/media/*)
+    echo "FAIL: run this test from a WSL-native copy, not a mounted Windows path." >&2
+    exit 2
+    ;;
+esac
+
+cd "${repo_root}"
+
+for command in mysql mysqladmin node npm openssl; do
+  command -v "${command}" >/dev/null || {
+    echo "FAIL: required command is missing: ${command}" >&2
+    exit 2
+  }
+done
+
+mysqladmin ping --silent >/dev/null || {
+  echo "FAIL: local MySQL is not responding." >&2
+  exit 2
+}
+
+mysql_version="$(mysql --batch --skip-column-names -e 'SELECT VERSION()')"
+mysql_major="${mysql_version%%.*}"
+if [[ "${mysql_major}" != "8" ]]; then
+  echo "FAIL: MySQL 8 is required; actual version is ${mysql_version}." >&2
+  exit 2
+fi
+
+mysql --batch --skip-column-names -e 'SELECT CURRENT_USER()' >/dev/null
+
+run_id="$(date -u +%Y%m%d%H%M%S)_$$_$(openssl rand -hex 3)"
+database="qipai_m01b_test_${run_id}"
+username="qmb_$$_$(openssl rand -hex 4)"
+password="$(openssl rand -hex 24)"
+created=0
+
+cleanup() {
+  if [[ "${created}" == "1" ]]; then
+    mysql --batch --skip-column-names <<SQL >/dev/null
+DROP DATABASE IF EXISTS \`${database}\`;
+DROP USER IF EXISTS '${username}'@'127.0.0.1';
+SQL
+  fi
+}
+trap cleanup EXIT INT TERM
+
+create_temporary_resources() {
+  created=1
+  mysql --batch --skip-column-names <<SQL >/dev/null
+CREATE DATABASE \`${database}\` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+CREATE USER '${username}'@'127.0.0.1' IDENTIFIED BY '${password}';
+GRANT ALL PRIVILEGES ON \`${database}\`.* TO '${username}'@'127.0.0.1';
+SQL
+}
+
+if [[ "${1:-}" == "--force-failure" ]]; then
+  create_temporary_resources
+  exit 23
+fi
+
+if [[ "${1:-}" == "--cleanup-probe" ]]; then
+  before_database_count="$(mysql --batch --skip-column-names -e "SELECT COUNT(*) FROM information_schema.SCHEMATA WHERE SCHEMA_NAME LIKE 'qipai_m01b_test_%'")"
+  before_user_count="$(mysql --batch --skip-column-names -e "SELECT COUNT(*) FROM mysql.user WHERE User LIKE 'qmb_%' AND Host = '127.0.0.1'")"
+  set +e
+  bash "${BASH_SOURCE[0]}" --force-failure
+  probe_status=$?
+  set -e
+  [[ "${probe_status}" == "23" ]] || {
+    echo "FAIL: cleanup probe did not produce the expected interrupted status." >&2
+    exit 1
+  }
+  after_database_count="$(mysql --batch --skip-column-names -e "SELECT COUNT(*) FROM information_schema.SCHEMATA WHERE SCHEMA_NAME LIKE 'qipai_m01b_test_%'")"
+  after_user_count="$(mysql --batch --skip-column-names -e "SELECT COUNT(*) FROM mysql.user WHERE User LIKE 'qmb_%' AND Host = '127.0.0.1'")"
+  if [[ "${before_database_count}" != "${after_database_count}" || "${before_user_count}" != "${after_user_count}" ]]; then
+    echo "FAIL: temporary MySQL resources survived an interrupted test." >&2
+    exit 1
+  fi
+  echo "PASS: interrupted-run cleanup removed the temporary database and account."
+  exit 0
+fi
+
+create_temporary_resources
+
+export NODE_ENV=test
+export QIPAI_MYSQL_HOST=127.0.0.1
+export QIPAI_MYSQL_PORT=3306
+export QIPAI_MYSQL_DATABASE="${database}"
+export QIPAI_MYSQL_USER="${username}"
+export QIPAI_MYSQL_PASSWORD="${password}"
+export QIPAI_MYSQL_CONNECTION_LIMIT=2
+
+echo "INFO: MySQL ${mysql_version}; running M01-B migration roundtrip in a temporary database."
+npm --prefix backend run test:mysql:migration
+echo "PASS: M01-B live MySQL migration roundtrip completed."