returning half of a gift; half-return gift
Refers to the Japanese custom of giving back a gift worth about half the value of a received celebratory or condolence gift, often as a thank-you gesture.
Since I received a condolence gift, I sent a half-return gift.
The custom of half-return gifts varies by region.
half backstitch
Compound of 半 (half) and 返し (returning), from the verb 返す (to return). The term directly describes the practice of giving back half the value of a received gift.