The Children of Shiunji Family summary:
The seven brothers and sisters of the Shiunji family, who live in the mansion of Setagaya, are both talented and well-known in the streets. Shin, the eldest son, has spent his time cherishing his family while being swayed by five sisters with strong personalities. Meanwhile, at the 15th birthday party of Koto, his father tells him a surprising fact.
"You are not real brothers and sisters."
The new fate that I thought would continue to live with seven people while being swayed by my sisters begins to move!