Son of Joe Gibson, Junior is of the same age as Goro. When Junior's parents divorced because his mother could not stand life in Japan, whereas Gibson wanted to remain in Japan pitching until he had found out how to make up for the incident with Goro's father, Honda, Junior stayed with his father in Japan. When his mother and sister died in a traffic accident in America, Junior became resentful towards his father and the deceased Honda. His motivation to play baseball was fueled by the desire to defeat his father. He is an extremely talented batter, being able to bat both left and right as a switch hitter. He played for the AAA Oklahoma Falcons, the MLB team Texas Raiders, as well as the USA Team during the Baseball World Cup. He typically fields the third base and Goro's rival.