Keita has two step-sisters (without blood-relation) who love him in a lustful way and have no problems expressing it, they even like to compete about it; much to the laughs of his friends (which he usually endures without problems). One day they come to his school to give him his lunch, he gets annoyed due to the href='http://atm.zenaku.net' onclick="window.open(this.href, '_blank'); return false;">ATMosphere and explodes on them, to counter attack his anger they confess their tender feelings for him in front of everyone and leave. Feeling sorry he chases after them and says that he'll study hard in order to get in the same highschool as them.