Set two years after the Red Hole incident and eight years before the start of the series, Senji Kiyomasa is a police officer using his Branch of Sin to fight criminals, but has a little temper. One day, he rescues a boy named Izuru who stole from a gang called Goreless Peace. After returning him to an orphanage, Senji encounters Goreless Peace's chairman, Keigo Ugachi, who also possesses a Branch of Sin. When Senji refuses to join him, he burns down the orphanage and kills everyone in it, including Izuru and the caretaker. Devastated and angered, Senji goes to confront Keigo, gaining some support from his police acquaintances. However, Senji finds himself in a giant spider web formed from Keigo's powers. When Keigo injures Senji's superior Domon, Senji manages to break the sound barrier and break through Keigo's ability, barely holding back enough to not kill him.
—http://deadmanwonderland.wikia.com/wiki/Red_Knife_Wielder