Kageyoshi, Manmaru, Senkuu, and Rakshas── Until the four members of Otokojuku's "Shitennou" found a bond stronger than blood... There was an unknown fateful encounter and an unimaginable deadly battle!! How did they meet, build an unshakable bond, and form "Shitennou"──!?　The ultimate spin-off that delves into their roots!!!! The story begins with the four of them each entering Otokojuku as first-year students!! Then, a fierce battle begins with the rough group "Demonic Fourth-year Students," who even the instructors couldn't handle and who had been erased from Otokojuku!! A must-read for fans: the shocking story behind the birth of Otokojuku's "Shitennou" is here!!!