It was love at first sight for Aihara Kotoko as top student Irie Naoki delivers a speech on the first day of high school. After two years of secret admiration, "I don't want it" is the rejection she gets when she plucks up enough courage to hand him a love letter. Rejected, Kotoko vows to give him up. By a twist of fate, Kotoko's house collapses; her dad and her put up at a friend's place, who happens to be Naoki's father.
And thus, life with Naoki begins and Kotoko's love for Naoki rekindles again. Much laughter ensues when scatterbrain Kotoko makes her countless advances — supported by Naoki's wacky mother, Noriko — on ice-cold Naoki, who hates girls and is a genius at practically everything from studies to sports.