Hearing loud noises and discovering a weird feeling on his crotch, Koutarou wakes up to find two beautiful girls, Chloe and Alicia, claiming ownership of his penis. Ten years ago, Koutarou had apparently made a promise of marriage to each of them. With Koutarou unsure how to respond, Alicia is the first to make a move with a kiss, and soon, the whole situation snowballs into a "contest" between the two girls. [Written by MAL Rewrite]