恩返(おんがえ)しrequital of a favour (favor), repayment (of an obligation, kindness, etc.)

お世話(せわ)になった人(ひと)に恩返(おんがえ)しをする。

I will repay the kindness to the person who took care of me. {requital of a favour (favor), repayment (of an obligation, kindness, etc.)}

弟子(でし)が恩返(おんがえ)しをしてくれた時(とき)は嬉(うれ)しかったです。

I was happy when my disciple repaid the favor. {requital of a favour (favor), repayment (of an obligation, kindness, etc.)}

僕(ぼく)はこれから育(そだ)ててくれた両親(りょうしん)に恩返(おんがえ)しをするつもりです。

I intend to repay the favor to the parents who have raised me from now on. {requital of a favour (favor), repayment (of an obligation, kindness, etc.)}

ホームレス：「家(いえ)まで貸(か)してくれるなんて…恩返(おんがえ)しのしようもありません…！」

Homeless Person: "Lending me your home... I have no way to repay this kindness!" {requital of a favour (favor), repayment (of an obligation, kindness, etc.)}

傲慢(ごうまん)なタケルときたら、お世話(せわ)になった人(ひと)に恩返(おんがえ)しもしないで去(さ)ろうとしている。

When it comes to arrogant Takeru, he's trying to leave without even repaying the kindness shown to him by those who helped him out. {requital of a favour (favor), repayment (of an obligation, kindness, etc.)}