胸中

1. Origins, structure, and basic meaning

• Structure: 胸中 (きょうちゅう) is a noun for feelings or thoughts held within one's heart.
• Basic usage: It describes anxiety kept unspoken or a character's inner thoughts revealed through a diary.
  • 彼は胸中の不安を誰にも語らなかった。 — He told no one about the anxiety in his heart.
  • 主人公の胸中が日記の一節から伝わってくる。 — A line in the diary reveals the protagonist's inner thoughts.

2. Common pitfalls and similar expressions

• Inner state, not anatomy
  • In this use, 胸中 refers to a person's inner state rather than the physical chest. An emotion held inside can follow it with の, as in 胸中の不安.