There was a boy, who read the ecchi books about the oppai and having fantasized about the oppai(big breast) ladies every time he thinks about it. Then one day, he received a bunch of sex tickets and the letter, as well as the person’s bust size on the reverse of each cards. Found himself clueless, the girl named Nil explained that he was quilified into the game(or so…), and so his quest to be the Oppai king begins….