監獄学園 [Purizun Sukūru] [Prison School]

A co-ed Japanese high school suddenly ends its long-standing policy of strict gender segregation, but when five boys from the newly formed "Penis Club" are caught attempting to peep on the girls' bath, they are sentenced to a bizarre, sadistic prison-like detention run by the school's secret disciplinary committee. Published by Kodansha from 2011 to 2018, this 28-issue series by creator Akira Hiramoto is a masterclass in escalating absurdity, blending ecchi comedy with elaborate, tension-filled escape plots and deadpan reactions to increasingly humiliating punishments. It stands as a cult classic for its unflinching commitment to its own ridiculous logic, turning a simple premise into a sprawling, perverse, and surprisingly compelling saga of teenage desperation and institutional cruelty.