It's hard to believe, but Yoshiko Hanabatake consistently scores a big fat zero on all her tests and has an inexplicable obsession with bananas. Even her own mother has given up on her due to her nonsensical antics. Thankfully, her childhood friend Akuru "A-kun" Akutsu is the only one who can handle her crazy behavior. A-kun is a diligent and intimidating person who isn't afraid to use force to put an end to Yoshiko's foolishness. Despite his efforts to set her straight, she never seems to learn and continues to act out with other odd individuals. Every moment with her is unpredictable, and despite A-kun's best efforts to control her absurdity, Yoshiko's extreme stupidity always prevails.