こころをおににする
Meanings
Expression
Verb (する)
1. to harden one's heart
Composed of
mind; heart; spirit; the meaning of a phrase (riddle, etc.)
ogre; demon; spirit of a deceased person; ogre-like person (i.e. fierce, relentless, merciless, etc.); it (in a game of tag, hide-and-seek, etc.); very