Shiunji-ke no Kodomotachi

Arata Shiunji lives in an unusually dazzling household: two brothers and five sisters, all intelligent, attractive, and raised together in a wealthy family where teasing and chaos are part of daily life. His sisters often mock his complete lack of romantic success, but Arata values his family above everything and has never imagined those bonds could become anything else.

On the youngest sibling's 15th birthday, their father reveals a secret kept for years: the Shiunji children are not related by blood. Everyone insists that being a family will still mean exactly what it always has, yet feelings that were easy to dismiss under the label of sibling affection suddenly become much harder to ignore. Arata is left trying to protect the home he treasures while its familiar relationships begin to take on an entirely new meaning.