Kiyosumi Katou

A top student of Doppo Orochi, who left the dojo after having enough of Doppo's "weak" training regime and trained around the world. He returns to Japan after finding out the Underground tournaments. Katou's attitude is best described as arrogant, but usually being the butt of a joke; especially around Doppo, Katsumi, Tokugawa, and Baki, however, it is shown that he truly admires and cares for Doppo.

(Source: Wikipedia)