Goro was an assassin for the Yakuza, who always boasted that only the blade of a dead man could kill him. He eventually came upon a young girl name Reiko; whose father owed Goro numerous debts. He took the young girl to be his property until the day he died; making her his pupil/slave.
Goro was eventually hired by a drug lord, Dai-Kumo, to kill Tyger Tiger's body guard, Patch (aka, Wolverine). Goro managed to "kill" Patch with a sword through the chest. However, he was not prepared for Patch to return and indeed kill him.