In the future, the world's overpopulation problem is traced back to Junta Momonari and his supernatural ability to seduce women, which gains him the title of "Mega Playboy". Though you'd never know it, since currently Junta's powers have not woken up, and he's just your typical Unlucky Everydude with a literal allergy to women... that causes him to throw up whenever he sees a naked girl that isn't his mother. Which happens in front of Tomoko Saeki, the most beautiful girl at his school.