筒抜け

1. Origins, structure, and basic meaning

• Structure: 筒抜け (つつぬけ) describes sound carrying straight through or confidential information becoming fully exposed.
• Basic usage: Conversation may be 筒抜けだ through thin walls, while a secret can 筒抜けになる to everyone involved.

2. Common pitfalls and similar expressions

• Sound carrying and secrets leaking
  • The literal sound and figurative information senses differ, but both involve something passing through without being blocked.