Sho is the older brother of Eiji Shinjo and the mentor to his friend Kayin Amoh. He taught the two their fighting styles and as such they use variations of his combat style.
During the tournament Sho encounters Cupido, who serves the tournament Master. The pair fall in love and would eventually have a son. Sho eventually loses to his younger brother and satisfied that his brother has become strong enough entrusts Eiji with his son's care.