Five years ago, in the middle of winter, Kosuke Kurono's beloved sister was raped and murdered. Ever since then, he has devoted his life to revenge. When he finally avenged his sister's death, Kurono had nothing left to live for, and he decided to end his own life, too. But instead, he was reincarnated into another world, and given the Black Magic wielded by the great heroes of the past. Being told that his sister might have reincarnated into this world, too, he set out to look for her! (Source: Comic Ride, translated)