Hachimitsu Academy, a prestigious and formerly all-girls boarding school on the outskirts of Tokyo, makes a historic decision to admit male students for the first time. The dream of attending a school filled with thousands of girls turns into a bewildering reality for Kiyoshi Fujino, who quickly discovers that he is one of only five boys enrolled alongside over a thousand female students. His fellow male students are the eccentric and brilliant strategist Takehito Gakuto Morokuzu, the pessimistic blond Shingo Wakamoto, the sickly and ant-obsessed Jouji Joe Nezu, and the gentle giant with masochistic tendencies, Reiji Andre Andou.

Their hopes of a carefree high school life are immediately crushed by the draconian laws enforced by the school’s secretive Underground Student Council. Led by the stern and boy-hating president Mari Kurihara, alongside her intimidating vice-president, the whip-wielding Meiko Shiraki, and the martial artist secretary Hana Midorikawa, the council ruthlessly polices the male students. After a failed plan to peep on the girls' bathhouse, the five boys are arrested and sentenced to one month in the school’s notorious prison block, a grim facility where they are subjected to forced labor, humiliating punishments, and constant surveillance.

Desperate to escape their imprisonment, the boys plot a jailbreak so Kiyoshi can keep a sumo wrestling date with the kind-hearted Chiyo Kurihara, Mari’s younger sister, for whom he has developed feelings. The breakout, masterminded by Gakuto, leads to a series of tense and absurd confrontations, including a prolonged struggle in a bathroom stall where Kiyoshi accidentally urinates on Hana, creating a complex and volatile relationship of shame and revenge between them. The escape attempt ultimately fails, and Kiyoshi is nearly expelled, only to be saved by Chiyo’s impassioned plea. In retaliation, Mari initiates Operation DTO, a scheme to have all five boys permanently expelled by exploiting their internal conflicts and weaknesses.

The prison sentence pushes the bonds of friendship and loyalty to their breaking point. Shingo is coerced into becoming an informant for the Underground Student Council in exchange for privileges, while Andre’s masochistic devotion to Meiko is exploited. Meanwhile, Hana becomes obsessively fixated on Kiyoshi, determined to exact her revenge. The narrative builds toward a climactic confrontation as the boys discover the secret that could bring down the Underground Student Council: Mari’s father, the school’s eccentric chairman, has a fetish for South American posteriors, and his secret collection is hidden within the school. The boys must race against time to expose this secret and prove their innocence before their expulsion becomes final. The 2015 Japanese live-action television drama, directed by Noboru Iguchi, spans nine episodes and follows the major narrative arcs of the original manga, capturing the over-the-top physical comedy, tense strategic battles, and perverse predicaments that define the story.