S.O.B. are an influential and enduring japanese hardcore punk and thrashcore band who were, along with similar thrashcore bands like Siege, pioneers and precursors of grindcore. The group debuted in 1986 with the single Leave Me Alone. In 1990, S.O.B. found international recognition with their split 7" EP with British band Napalm Death, who are also pioneers of this genre with bands like Terrorizer and mostly Repulsion.