Years before he was conceived Shiro Yoshida's mother was exposed to radiation from the nuclear bomb dropped on Hiroshima by the United States at the end of World War II. After giving birth, she died and Yoshida was left in the care of an uncle by his diplomat father.
While in the care of his uncle Yoshida was taught to be fervently anti-American. Suspecting his nephew was a mutant he was taken to the site of the Hiroshima bombing and upon contact with the irradiated soil Yoshida's mutation activated. Encouraged by his uncle, Yoshida mastered his abilities and vowed revenge upon the United States for his mother's death.
Attacking the United Nations and the Capital Building in Washington D.C., Yoshida was challenged by the X-Men. Persuaded by his father to cease his mission of destruction Yoshida's uncle fatally shot the diplomat. Driven to grief Yoshida in turn killed his uncle.
Protected by diplomatic immunity and considerable political wrangling, Yoshida returned to Japan to become its greatest champion, the mutant known as Sunfire.
Current Version:
Sunfire (Pestilence)
Former Versions:
Sunfire
