Born into a Japanese diplomatic family, Shiro Yoshida was always a high-strung, hot-tempered individual. Later, when is mutant powers for generating and channeling hot plasma developed, Shiro took on the guise of Sunfire and become Japan's premier champion! Feeling he owed more to himself than Professor X, he nonetheless joined Xavier's new team of X-Men. Sunfire's mutant powers also include a built-in force field and the ability to fly!