Being strict about eating sweets with 心を鬼にする
Idiom Explanation: Taking a hardhearted stance with 心を鬼にする
Having gained weight recently, Mie asks Komura to stop her from eating sweets at school, a difficult task as it’s White Day.
Komura repeatedly stops Mie from eating the cookies and chocolate she’s received as gifts. His resolve weakens as he finds it adorable how Mie tries to sneak a bite whenever he’s not looking.
- 小村:
- 「で…でもダメだ！ 三重さんが一度決めたことを破らせては… 心を鬼にしないと…！！」
- “But, that's no good! If I let Mie break her decision... I have to be strict for her sake!”
Key Points
心を鬼にする = “harden your heart and be strict, even if it feels cruel”
Here Komura means he has to stop Mie from eating sweets even though he feels bad for her.
The idiom often carries the nuance of being severe because you think it is necessary or ultimately good for the other person.
鬼 adds the image of acting harshly on purpose
The point is not that he literally becomes a demon, but that he must shut off his softness and act tougher than he wants to.
That matches the English “be strict for her sake” more closely than a flat “be mean”.
〜ないと = “have to” in casual speech
「心を鬼にしないと」 is short for a fuller “If I don’t harden my heart, that won’t work.”
In natural English here, it comes across as “I have to be strict.”
The earlier clause explains why he feels forced into this stance
「三重さんが 一度 決めたことを 破らせては…」 means “I can’t let Mie break a decision she made.”
That makes the idiom sound like reluctant resolve: he is talking himself into doing the hard thing.
See Also
- Kanji: Measures and degrees with 度