How to say "remorse" in Japanese

• 後悔こうかいJLPT N1approx.Common
  suru verb, transitive verb, intransitive verb, no-adjectiveThe broad word for the painful feeling of regret over something one has done or a choice one has made; use it for remorse felt over a decision or over words spoken in anger.
  今更いまさら後悔こうかいしても無駄むだだ。↗

  It's no use regretting it now.
• 反省はんせいJLPT N2approx.Common
  noun, suru verb, transitive verbRemorse as self-examination: being sorry for a fault of one's own and looking back over it so as not to repeat it; typical when apologizing for a mistake and vowing to do better.
  彼女かのじょは重大じゅうだいな過あやまちを後悔こうかいした、反省はんせいした。↗

  She showed her regret over the serious mistake.

For remorse over one's own actions, 後悔 is the broader word for the painful feeling of regret itself, while 反省 frames it as self-examination of a fault, with an eye to not repeating it.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 後悔こうかいregret
• 悔悟かいごremorse
• 悔恨かいこんregret
• 慙愧ざんきshame
• 反省はんせいregret