Sho had trained his younger brother Eiji and his friend Kayin Amoh in swordfighting. However, he eventually abandoned the pair, feeling that they would be able to get stronger without his guidance. Sho had then traveled the world as a lone warrior and became infamous for mercilessly defeating any other fighters rumored to have potential, among these being Kayin's father, who he killed from within the finals of the last tournament. When the first Toshinden tournament was announced, he secretly entered the event and encountered Cupido, a woman from the Secret Society. They fell in love and eventually had a son together, named Subaru. After the events of the third tournament, where Eiji had destroyed the Organization and its leader Abel, Sho finally faced his brother in a decisive battle and left Subaru in his care from within the end. Sho had then disappeared immediately afterwards once again and hasn't been heard from since.