Mariko Yashida was the daughter of Japanese crimelord Lord Shingen, leader of Clan Yashida. She first met the feral mutant Wolverine when the mutant heroes the X-Men sought the help of her cousin, the Japanese mutant hero Sunfire. Although initially frightened by the ferocious-looking Wolverine, Mariko found herself attracted to him. Similarly, Wolverine was charmed by her beauty and refined manner. The two spent a great deal of time together in Japan, ultimately falling in love when she visited him in New York.

However, Mariko was forced by her father to marry one of his criminal associates, Noburu-Hideki, a cruel man who beat her. When Wolverine learned of the abuse, she refused to leave with him, feeling duty-bound to obey her father’s wishes. Wolverine was subsequently drugged and challenged by Shingen to a duel, during which Mariko was unaware that Shingen was actually trying to kill Wolverine and was shocked when Wolverine retaliated with deadly force. Noticing her dismay, Wolverine lost heart and was defeated.

Shingen then ordered his operative Yukio to slay a rival crimelord, Katsuyori, who was himself intending to kill Hideki. Wolverine, having accompanied Yukio, battled the assassins in a berserker rage. Horrified, Mariko fled back to her father’s stronghold. Repulsed by Shingen’s crimes, she vowed to kill him to prevent further dishonor from falling on Clan Yashida. When Wolverine attacked the stronghold, Hideki attempted to flee with Mariko, threatening to kill her unless he was allowed to escape. Mariko was saved by Yukio who slew Hideki. Wolverine then slew Shingen in a savage duel, making Mariko head of Clan Yashida, and the two reunited lovers announced their engagement.

As the wedding approached, the X-Men’s long-time foe Mastermind used his psionic powers to compel Mariko to call off the wedding and strengthen Clan Yashida’s criminal ties. After Mastermind’s defeat, Mariko felt deep shame at the actions she had performed under his control. She vowed to break her Clan’s criminal connections, feeling that she could not marry Wolverine until she did so. To that end, Mariko became a force in the Japanese criminal underworld, however her authority was subsequently challenged by both by Matsu’o Tsurayaba, leader of the ninja clan the Hand, and by her own half-brother, the Silver Samurai. Wolverine and his allies fought the Hand on her behalf, but when Mariko sought to make peace, Tsurayaba had her poisoned. Wishing to avoid prolonged suffering, she asked Wolverine to grant her a quick death, which he reluctantly did.