Shouta, who's in love with his childhood friend Mei, hates Chika, who is a brother of Mei, because Chika always interferes with Shouta trying to confess his love to Mei. However, they accidentally have sex after the shocking news of Mei's new boyfriend…They try to forget the accident and now cooperate to break up Mei and her boyfriend, but one of their plans involves Chika disguising as a woman. Shouta cannot control the rising feeling he has for Chika in woman's clothes, even though he doesn't look like Mei at all...