The Nakano family, who live in a residential area, is a large family of seven. Since their parents are often not at home, they live with Haruki, Yumezuki, Yayoi, Hanetsuki, and Sakizuki, one boy and four girls. As the eldest son, Haruki always has to deal with four sisters with very different personalities. Although he sometimes makes them angry or treats them like toys, he cannot erase their warm family feelings.