Kamiya Nao

After the death of his grandfather, Yoshisuzu Shougo moves into the mansion left to him. He lives there with Otosumi Youko, the maid. Shougo often has sex with Youko, but, while in the half asleep state following orgasm, he always sees a vision of a beautiful girl. The girl's name is Reiko, whose picture adorns a wall within the mansion.

Daisuke is a new teacher in school. He became popular with everyone in a matter of days. He conducts a class that allows his students to role-play as whatever they wish to be when they graduate, but some say this is a plot to spend extra time with the girls, and the girls expect more then just lessons.

A female medical investigator is developing a drug that can potence the posibility of an impotent female or male to procreate. But the true reason is that she is an hermaphrodite (dual sex) but her both sexual organs are impotent an unable to procreate. So she develops that drug, making two version, the blue one for males and the red for females. But as any new medicine she must try it out first, there is when her nurse assistants became useful and then she must analyse each reaction in each subject, including herself, expecting some interesting outcomes.

On spring break, Daisuke is excited for his vacation on a tropical island for some well deserved relaxation and girl watching. He finds himself quite inexplicably popular with the ladies as well. Nao and Mitsugu follow him there as well competing, as usual, for his attentions. Meanwhile he meets his cousin Maya again after a long time as well as the wild Kanae and her friend Mika.