While in New York, Logan, better known to others as Wolverine, fell in love with a Japanese woman named Mariko. When she suddenly disappears, Logan comes to Japan in search of her.
Mariko's father, Yashida Shingen, is the head of Kuzuryuu, a yakuza organization. It is in Shingen's mansion that Logan finds Mariko, who had been brought back to Japan against her will. It is Shingen's intention for Mariko to marry an influential person so as to seal a political alliance between that person and Kuzuryuu.
During Logan's attack on Shingen's mansion, in a fight with his bodyguards, Logan is struck by a needle. The needle is coated with a poison which greatly reduces his regenerative abilities. In his weakened state, he is no match for Shingen and is defeated in a duel and left for dead.
Logan is discovered on the verge of death by the mysterious Yukio. With Yukio's ministrations, Logan eventually recovers and the two join together in a second bid to take down Shingen.