A retelling of the prison arc from the manga RIKI‑OH! The story follows Saiga Riki‑Oh, a young man blessed with inhuman strength. After exacting revenge on the yakuza boss responsible for his girlfriend’s death, he is sent to a maximum‑security prison operated by a private organization. The prison is divided into four blocks, each overseen by a prisoner who is part of the Gang of Four. The first block is run by Hai, a tattooed knife‑wielder who manages his block with a mafia‑style family structure. The second is overseen by Tarzan, a giant man famed for his incredible strength. The third block is led by Huang Chaun, an effeminate fighter who cultivates opium within the prison. The final …