diff --git a/.changeset/fix-session-stray-file-startup.md b/.changeset/fix-session-stray-file-startup.md
new file mode 100644
index 00000000000..66c91bf04e9
--- /dev/null
+++ b/.changeset/fix-session-stray-file-startup.md
@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Fix `kimi -c` failing to start with a storage error when a stray file is present in the session directory.
diff --git a/packages/agent-core-v2/src/persistence/backends/node-fs/fileStorageService.ts b/packages/agent-core-v2/src/persistence/backends/node-fs/fileStorageService.ts
index 7104423e6ca..5ed544d7eab 100644
--- a/packages/agent-core-v2/src/persistence/backends/node-fs/fileStorageService.ts
+++ b/packages/agent-core-v2/src/persistence/backends/node-fs/fileStorageService.ts
@@ -20,8 +20,9 @@ const WATCH_DEBOUNCE_MS = 150;
 const TORN_READ_RETRIES = 3;
 const TORN_READ_RETRY_DELAY_MS = 15;
 
-function isEnoent(error: unknown): boolean {
-  return (error as NodeJS.ErrnoException).code === 'ENOENT';
+function isMissing(error: unknown): boolean {
+  const code = (error as NodeJS.ErrnoException).code;
+  return code === 'ENOENT' || code === 'ENOTDIR';
 }
 
 export class FileStorageService implements IFileSystemStorageService {
@@ -42,7 +43,7 @@ export class FileStorageService implements IFileSystemStorageService {
       try {
         bytes = await readFile(filePath);
       } catch (error) {
-        if (isEnoent(error)) return undefined;
+        if (isMissing(error)) return undefined;
         throw toStorageIoError(error, { path: filePath, op: 'read' });
       }
       if (attempt >= TORN_READ_RETRIES) return bytes;
@@ -72,7 +73,7 @@ export class FileStorageService implements IFileSystemStorageService {
         yield chunk as Uint8Array;
       }
     } catch (error) {
-      if (isEnoent(error)) return;
+      if (isMissing(error)) return;
       throw toStorageIoError(error, { path: filePath, op: 'read' });
     }
   }
@@ -144,7 +145,7 @@ export class FileStorageService implements IFileSystemStorageService {
     try {
       entries = await readdir(this.scopePath(scope));
     } catch (error) {
-      if (isEnoent(error)) return [];
+      if (isMissing(error)) return [];
       throw toStorageIoError(error, { path: this.scopePath(scope), op: 'list' });
     }
     return prefix === undefined ? entries : entries.filter((entry) => entry.startsWith(prefix));
@@ -155,7 +156,7 @@ export class FileStorageService implements IFileSystemStorageService {
     try {
       await unlink(filePath);
     } catch (error) {
-      if (isEnoent(error)) return;
+      if (isMissing(error)) return;
       throw toStorageIoError(error, { path: filePath, op: 'delete' });
     }
   }
@@ -165,7 +166,7 @@ export class FileStorageService implements IFileSystemStorageService {
     try {
       return (await stat(filePath)).size;
     } catch (error) {
-      if (isEnoent(error)) return undefined;
+      if (isMissing(error)) return undefined;
       throw toStorageIoError(error, { path: filePath, op: 'stat' });
     }
   }
@@ -175,7 +176,7 @@ export class FileStorageService implements IFileSystemStorageService {
     try {
       return (await stat(filePath)).mtimeMs;
     } catch (error) {
-      if (isEnoent(error)) return undefined;
+      if (isMissing(error)) return undefined;
       throw toStorageIoError(error, { path: filePath, op: 'stat' });
     }
   }
@@ -263,7 +264,7 @@ export class FileStorageService implements IFileSystemStorageService {
       await syncDir(dir);
       this.syncedDirs.add(dir);
     } catch (error) {
-      if (!isEnoent(error)) throw error;
+      if (!isMissing(error)) throw error;
     }
   }
 }
diff --git a/packages/agent-core-v2/src/persistence/interface/storage.ts b/packages/agent-core-v2/src/persistence/interface/storage.ts
index 0449c399f31..3a26c3f2ffd 100644
--- a/packages/agent-core-v2/src/persistence/interface/storage.ts
+++ b/packages/agent-core-v2/src/persistence/interface/storage.ts
@@ -95,6 +95,7 @@ const REASONS: Record<StorageIoErrorCode, string> = {
 function mapErrno(errno: string | undefined): StorageIoErrorCode {
   switch (errno) {
     case 'ENOENT':
+    case 'ENOTDIR':
       return StorageErrors.codes.STORAGE_NOT_FOUND;
     case 'EACCES':
     case 'EPERM':
diff --git a/packages/agent-core-v2/test/app/sessionIndex/sessionIndex.test.ts b/packages/agent-core-v2/test/app/sessionIndex/sessionIndex.test.ts
index 63146d8ec57..3c2a9657edd 100644
--- a/packages/agent-core-v2/test/app/sessionIndex/sessionIndex.test.ts
+++ b/packages/agent-core-v2/test/app/sessionIndex/sessionIndex.test.ts
@@ -947,6 +947,22 @@ describe('FileSessionIndex (read model)', () => {
     expect(await store.count({ workspaceIds: [workspaceId] })).toBe(2);
   });
 
+  it('ignores non-directory junk entries (e.g. .DS_Store) in a workspace directory', async () => {
+    await seedSession('a', { title: 'a', createdAt: 1, updatedAt: 2 });
+    await fsp.writeFile(join(sessionsDir, workspaceId, '.DS_Store'), 'junk');
+
+    const store = build();
+    const status = await store.prepare();
+    expect(status).toEqual({ state: 'ready', generation: 1, degradedCount: 0 });
+
+    const page = await store.listRecent({ workspaceIds: [workspaceId] });
+    expect(page.items.map((s) => s.id)).toEqual(['a']);
+    expect(await store.count({ workspaceIds: [workspaceId] })).toBe(1);
+
+    await store.reconcileNow();
+    expect(store.status().state).toBe('ready');
+  });
+
   it('the first read kicks one initial projection and shares its authoritative scan', async () => {
     await seedSession('a', { title: 'a', createdAt: 1, updatedAt: 3 });
     await seedSession('b', { title: 'b', createdAt: 2, updatedAt: 2 });
diff --git a/packages/agent-core-v2/test/persistence/backends/node-fs/fileStorageService.test.ts b/packages/agent-core-v2/test/persistence/backends/node-fs/fileStorageService.test.ts
index e8f140c4a2a..12b20f49a2c 100644
--- a/packages/agent-core-v2/test/persistence/backends/node-fs/fileStorageService.test.ts
+++ b/packages/agent-core-v2/test/persistence/backends/node-fs/fileStorageService.test.ts
@@ -4,6 +4,8 @@ import { tmpdir } from 'node:os';
 import { join } from 'pathe';
 import { afterEach, beforeEach, describe, expect, it } from 'vitest';
 
+import { toStorageIoError } from '#/persistence/interface/storage';
+
 import { FileStorageService } from '#/persistence/backends/node-fs/fileStorageService';
 
 const isWin = process.platform === 'win32';
@@ -86,6 +88,29 @@ describe('FileStorageService — error translation', () => {
       details: { op: 'write', errno: expect.any(String) },
     });
   });
+
+  it('maps ENOTDIR to storage.not_found instead of io_failed', () => {
+    const error = toStorageIoError(
+      Object.assign(new Error('not a directory'), { code: 'ENOTDIR' }),
+      { path: join(dir, 'scope', 'entry', 'state.json'), op: 'stat' },
+    );
+    expect(error.code).toBe('storage.not_found');
+    expect(error.details).toMatchObject({
+      path: join(dir, 'scope', 'entry', 'state.json'),
+      op: 'stat',
+      errno: 'ENOTDIR',
+    });
+  });
+
+  it('treats a path through a regular file as missing for read/mtime/size', async () => {
+    const svc = new FileStorageService(dir);
+    await mkdir(join(dir, 'scope'), { recursive: true });
+    await writeFile(join(dir, 'scope', '.DS_Store'), 'junk');
+
+    expect(await svc.read('scope/.DS_Store', 'state.json')).toBeUndefined();
+    expect(await svc.mtime('scope/.DS_Store', 'state.json')).toBeUndefined();
+    expect(await svc.size('scope/.DS_Store', 'state.json')).toBeUndefined();
+  });
 });
 
 describe('FileStorageService — writeStream', () => {