sho shinjo
The mysterious older brother of Eiji Shinjo. Sho vanishes some time while Eiji is growing up; it's discovered that Sho joined a previous Toushinden tournament and won after killing Kayin Amoh's adoptive father, then worked for the Himitsu Kessha as an assassin (though it didn't seem to be his choice). Sho can be fought as an unlockable optional boss in the first three games. Subaru Shinjo is Sho's son, and the mother is assumed to be another assassin named Cupido, who likewise shares the same burdens of killing that Sho does.