Haruki Nakano leads a typical high school existence, except that his mother is away and he lives in an apartment with his four sisters. The oldest, Mutsuki, has a nasty habit of falling asleep in his bed, the junior high student Yayoi, who smacks him whenever something unpleasant happens, and the elementary school twins, Uzuki and Satsuki, who like playing pranks on their elder brother. Haruki is trapped in a house with four girls and must deal with a variety of difficulties. Life in Danchigai is never dull, whether it's going grocery shopping, watching horror movies, or practicing kissing!