One of the five new male students who commits voyeurism in the school bathing area alongside his friends. He receives an ultimatum from the Underground Student Council to either serve a month in the Prison Block or face expulsion, ultimately choosing incarceration.
A budding external romance that provides Shingo a temporary emotional outlet but introduces complications due to his prison schedule.
A deteriorating bond within the imprisoned group, where Shingo's leadership turns against Kiyoshi, deepening internal divisions.
Explore the full interactive character relationship map of Prison School