Assassinations by the Mafia occur repeatedly in the underworld. Rumors of a mysterious organization called "Inferno" and its most powerful assassin name "Phantom" begin to surface. A young man embarked on a trip alone to the United States and runs into "Phantom" by accident. "Phantom" turned out to be a young girl about the same age as him. Erasing the young mans memories of his past, the "Phantom" trains him to become one of the top assassins in the organization. In a violent and lawless world, his journey begins...