Kenichi Kokuhou

Kenichi became lost in the mountains as a small child. A foster father raised Kenichi and taught him karate; when Kenichi was 15 the foster father told Kenichi about his background and the teenager returned to the civilized world alongside his trusty companion Flipper. There he reunites with his biological family. He possesses superhuman strength, but lacks knowledge and understanding of etiqeutte.

(Source: Wikipedia, edited)