expression, noun
one's heart; one's inner thoughts; one's true feelings
Refers to what one truly thinks or feels inside, often contrasted with outward expression. Common in phrases like 心の内を明かす (reveal one's inner thoughts).
彼はなかなか心の内を見せない。
He rarely shows his true feelings.
心の内を打ち明けられる友達がほしい。
I want a friend I can confide my inner thoughts to.
本音 is one's real intention or honest opinion, often used in contrast to 建前 (public stance). 心の内 is broader, encompassing emotions and unexpressed thoughts.
心中 is a more formal or literary term for 'in one's heart/mind', often used in set phrases. 心の内 is more conversational and emphasizes the hidden inner world.
Compound of 心 (heart, mind) + の (possessive particle) + 内 (inside). The reading うち for 内 is the native Japanese word for 'inside'.