Yoshiko Hanabatake, a complete idiot with a penchant for bananas, repeatedly earns zero on her tests, much to the despair of her mother. Her childhood friend, the serious and studious A-kun, takes on the challenging role of reigning in her absurdity. Despite his efforts to stop her nonsensical antics, Yoshiko's idiocy knows no bounds, attracting other quirky individuals into her chaotic world. A-kun's struggle to control her madness is a constant battle, as Yoshiko's unpredictable behavior keeps the duo on their toes.