Kyotaro Higawa

Kyotaro is a 17 year old boy who just wants to live an ordinary life and maybe get a girlfriend. However that is not possible due to the fact that he is the son of a Yakuza boss. He is ashamed of this always avoiding anything that has to do with the mafia. One day his life is drastically changed when a girl named Kumiko appears in front of him claiming to be his halfsister.