Kubota Makoto's job as the head of the Izumo Group's youth gang kept him pleasantly occupied with yakuza wars, mahjong and assassinations. Until the day he stumbled upon a strange drug called Wild Adapter that produces bizarre side-effects including death. Forever changed, Kubota becomes entangled with a drifter named Minoru Tokito, and the two form an unlikely companionship that draws them deeper into the mystery of Wild Adapter.