Until one day Ryo learned that his stepmother, Madoka, was indebted to the Yotsuya family, he offered to sell himself and work for Akie Yotsuya, the head of the family. However, he had no idea what was in store for him in the mansion; initially, it was just Ryo, Akie, and Fumi, the maid. However, two more people soon moved in: Reiko, Akie's sister... and Madoka, Ryo's mother. Eventually, Ryo learned that the four women he shared the mansion with were related in more ways than one.