Yoshiko Hanabatake is a complete and total moron. Her stupid activities have caused even her own mother to lose hope, since she has continuously scored zeroes on all of her tests and is captivated by an absurd infatuation with bananas. Akuru "A-kun" Akutsu, a childhood buddy, is the only one who can keep her sanity in check. Though he complains about Yoshiko's foolish conduct, the studious but scary A-kun is always ready to put an end to it, and has no qualms about employing physical force. Unfortunately, no matter how many times he tries to reason with her, she only goes back to her normal antics, even dragging in some other oddballs with her.