Juujika no Rokunin

Throughout sixth grade, Shun Uruma was dubbed "Experiment A" by five of his classmates and subjected to constant torture. Despite holding on by a thread, Uruma's bullies ultimately crossed a line when they began targeting his family. With nobody left but his grandfather, Uruma knew he had endured enough. Fueled by his desire for revenge, Uruma implored his WWII veteran grandfather to guide him down a path of vengeance. After four years of grueling training, Uruma set out on a brutal journey of retribution to hunt down the five monsters who made his school life a living hell.