Private boys' school Shirotsu Gikou High School is the setting for a chaotic school comedy centered on the new teacher Onigashima, whose name and appearance contrast in a way that immediately draws attention. Onigashima is appointed as the advisor of the art club on his first day, and when he heads to the club room, he finds not a quiet group of students but the school's most notorious troublemaker, Momotaro, and his eccentric crew. The art club members are a collection of wildly individual personalities, with Momotaro being the most free-spirited and impossible to control. Onigashima tries to fulfill his role as a responsible teacher and rein in the unruly students, but Momotaro and the others refuse to listen to anything he says, leading to a high-energy, slapstick daily routine. The story unfolds through a series of comedic episodes as the well-meaning but hapless Onigashima gets dragged into the art club's chaotic activities while trying to maintain some semblance of order. The series spans their time together through the school year, including festival preparations, misunderstandings, and the growing bond between the exasperated teacher and the uncontrollable students, culminating in the graduation of the third-year members as their outrageous high school life comes to a close.