Touma arrives in Tokyo to take a college entrance exam, but is distracted in his hotel room by a young and very cute girl. She seems to know him, but he doesn't know her. At least he doesn't remember her. The pubescent vixen is Urara, his cousin. It seems she has a crush on Touma, but is angry when she sees some model, Mieko, all over him. Unfortunately, Touma failed his exam, but lies to Mieko about passing it. So now she attends college thinking that Touma also goes there. Thus Urara's mission to break them up begins.