恩おん返がえしをする

expression, suru verb (irregular)

return a favor; repay kindness

Used when someone does something good in return for a past kindness or help received. Often implies a sense of gratitude and obligation.

• いつか必かならず恩おん返がえしをします。

  I will definitely return the favor someday.

• 彼かれは育そだててくれた両りょう親しんに恩おん返がえしをするために、一いっ生しょう懸けん命めい働はたらいた。

  He worked hard to repay his parents for raising him.