Ane no Onaka wo Fukuramaseru no wa Boku
It is me to fill the stomach of my sister·姉のおなかをふくらませるのは僕
A high-school-age step-sister and an elementary-school-age step-brother live together after becoming a two-person household. The older sibling, Kyouko, has a lively and outgoing personality and enjoys professional wrestling, often teasing the younger boy, who is more reserved and easily embarrassed. They share daily life, taking turns preparing meals for each other as they navigate their cohabitation.