真しん骨こっ頂ちょう

noun

one's true worth; one's true self; what one is really made of

Refers to a person's genuine ability, character, or essence, often revealed under pressure or in a critical moment.

• ここで真しん骨こっ頂ちょうを発はっ揮きしなければならない。

  This is where I must show my true worth.

• 彼かれの真しん骨こっ頂ちょうは、困こん難なんな状じょう況きょうでこそ現あらわれる。

  His true self emerges precisely in difficult situations.