Modern times where people and others are living together. To schoolboy Sakurai Kazuto, "Different kind family(Myuu)" she was. It is girl succubus Hamasaki Shinon of a slow to mature in a lewd thing. The lover relation with her is excellent. However, Kazuto of the adolescence climax cannot be satisfied only by a platonic relation, Impatient every day is spent to proceed to the step more than the kiss. One day. It is Kazuto which managed to reach the first H in slow to mature Shinon, Immediately after, to faint by an extreme excitement and an excessive coming. It was obviously due to the nature of Shinon as Succubus.