Gena witnesses the murder of her son by a Japanees hit-man. He accidentally shoots the boy during a hit on a rival gang of bus operators. Gena then dedicates her life to revenge, and seeks out the gunman. But are the other (mystical) influences involved ?

When Nick Davis leaves prison after one year in solitaire, he is hired to operate forklift in a warehouse in the harbor owned by the Japanese Yakuza patriarch Isshin Tendo. The place is assaulted by the Italian Mafia leaded by Dino Campanela and Nick rescues and saves the life of Shuji Sawamoto, who is the representative of Yakuza interests in America. Shuji hires Nick to work for Yakuza and becomes his godfather in the family after his oath to join Yakuza. However, Nick is a lonely FBI undercover agent assigned to penetrate in the criminal organization. When the FBI discovers that Campanela is organizing a massive attack to destroy the Yakuza, Nick's boss Littman calls off the operation to leave the dirty work to the Italian Mafia. But the connection of Nick with Shuji and his goddaughter Yuko forces him to help his Japanese family.

Their vengeance is relentless, their method is ritual, their weapon is secret, and the motive is in their blood. In a heavily wooded private estate in the Malibu Hills, towering above the tumbling Pacific, millionaire CEO Kenji Takeo and his daughter, Miko, prepare for the arrival from Japan of Takeo's wife, Kumiko. But the calm of Solstice Canyon is shattered by a meticulously planned stealth attack on the Takeo home by a masked band of ninja assassins. In a flash, Takeo's guards are killed. The mansion is overtaken, Takeo is killed, and Miko is left for dead. Arriving at the bloody scene is Detective Jack Barrett who encounters Miko-the only living witness. In a state of shock, she repeats only one word like an eerie mantra: kokushibyu. In her native language, it means Black Death.