十字架のろくにん

Shun Uruma spends his sixth-grade year as the chosen target of five classmates led by Kyou Shigoku, enduring the abuse to spare his family. When the bullying escalates into an attack that kills his parents and leaves his little brother Kakeru in a vegetative state, Shun has nothing left to hold him back. He begs his grandfather, a veteran of a secret wartime unit, to train him for vengeance, then spends four years preparing to hunt down each of the five and make them pay.