If you want to lose your virginity, then you should all do it at the same time, right? The three of us have been friends since childhood, so we had a week of intimate, unprotected sex without our parents' company. DASS-390

The three have always been good friends, but Tomoki and Hikaru initially develop strong romantic feelings for Rimu. Rimu also recognizes them as opposite sexes and, since her parents are away, invites them to play with her. Tomoki and Hikaru are on the same page and won't elope with Rimu. However, Rimu is very interested in mischievous things and is frustrated that Tomoki and the others want to attack her, but they won't let her touch them.