August... until the end of summer vacation, a certain day when it approached in about one remaining week. The protagonist Ritsu Takashina in best friend's house who it had come to staying overnight, in sensation of buttocks assumed to be squishy wakes up.
(Laugh, Sorry, It has awoken?)
With the rest one's head on a person's lap, the name of the woman who shows a soft wide-open smile, Saginomiya Yura. It is a thought person from childhood for Ritsu, it was a woman who was mother of the best friend Masaki.
While concealed the feeling to Yura within the chest, Ritsu who has spent every day suffered mental anguish so far. However on that day, he witnesses the appearance of Yura that masturbates by chance in the bedroom.
(I'm sorry, Ri-kun... haaa, the aunt, it forgives...)
Yura where the sexual life with the husband doesn't go well, the scent of semen from Ritsu who is ingrained in the underwear is smelt, it climaxed. Ritsu who is excited runs in the bedroom, the thought is confessed to her as it is. Yura is touched by that seriousness while being surprised at a sudden thing, Ritsu were accepted only once.
With the loved person, it is Ritsu in the first sexual intercourse who becomes ecstasy. Ritsu who cannot give up the thought to Yura after the act ends, it proposes one to her.
[Until the husband comes back from the business trip, within one week, Yura-san will get pregnant!]
When it doesn't come true supposing, everything is forgotten with this days. This absurd proposal, Yura accepts after it was troubled. This way two "It is not good" the child making life raised the act.