A favour or kindness received from someone; a debt of gratitude or obligation to repay it.
彼には昔大きな恩がある。
I owe him a great debt of gratitude from long ago.
親の恩を忘れてはいけない。
You must not forget the debt of gratitude to your parents.
あの先生の恩に報いるために頑張ります。
I'll work hard to repay that teacher's kindness.