胸むね一ひとつ

noun

one's heart; one's true feelings

Refers to one's inner thoughts or emotions, often used in expressions like 胸一つに秘める (keep in one's heart).

• 彼かれはその思おもいを胸むね一ひとつに秘ひめていた。

  He kept that feeling deep in his heart.

noun

at one's discretion; in one's hands

Indicates that a decision or outcome depends entirely on one's own judgment or will. Often used in the pattern 胸一つで.

• 成せい功こうするかどうかは君きみの胸むね一ひとつだ。