A teenaged Kousaku has now moved in the home of his mother's friend, because she had died a while back. Its just so happens that the Yakuza family has four beautiful daughters, but the one daughter, Hibari, thats more beautiful than the rest of the daughters is actually a boy. Hibari just can't keep his hands off Kohsuka and so their crazy yet happy lives go on.

(Source: Anime News Network)