Genjuro is a feared samurai, and was a friend of Haohmaru' s, but soon became his rival. He has defeated the legendary Haohmaru in a past encounter, nearly killing him. He is a former student of Nicotine' s Because he holds no feelings for killing people, he was expelled by Nicotine. Now he hates Haohmaru because of this. He lives his life as a killer for hire and hunts down Haohmaru. In SS2, he joined with Mizuki to fight against Haohmaru but quickly betrayed Mizuki.
His mother was a slut who always slept with a different man everyday. One night, Genjuro snapped and killed the man that his mother brought into the house. As Genjuro tried to leave the house, his mother tried to kill him but Genjuro fought back and killed her instead. The scar he has on his back is from this incident. This was what caused him to have such a ruthless personality.
Genjuro also represents the Japanese card game called "Hanafuda." The little yellow frog that follows him around is also found on one of the cards in Hanafuda.