◆叩けば埃が出る Tatakeba hokori ga deru.
- 解釈：何事も、完全無欠ということはなく、探し出せば欠点や弱点が出てくるものだ。
- Literal：Dust comes out if you hit.
- Interpretation：If you investigate someone's past, you'll find plenty of dirt. Every man has his weak side. It has something to hide. Who are not fully complete. Who are not fully complete.
- 類義：垢（あか）は擦（こす）るほど出る。新しい畳も叩けば埃が出る。