都合のよいセックスフレンド？

Arahama Yuu has 5 sex-friends. One day, his easygoing sex-life reaches a precipice. One of his partners, Shimizu Misako, who is also a co-worker at his company, had been sleeping with him on the understanding that they would marry. However, he only considered her a sex-friend, and even revealed the existence of the other 4. Incensed, she has him gather the other 4 together in his apartment.

Shimizu discovers that Arahama has surrounded himself in the company of many beauties of differing personalities. Besides herself, the others are: Yanagi Ryouko who runs a cafe near Arahama's apartment; Hoshino Kotori, a schoolgirl of his acquaintance; Endou Makiko, who manages a large company; and Kamishima Aina whom he met on an on-line dating site.