He is Sanae's ex-husband. He remains in contact with Violence Rose and the Sumeragi family to maintain female wrestling.
Sanjo Kaoru is created by Jouji Manabe as the minor character in Ring X Mama manga series that originally ran in Takeshobo's NaMaiki! magazine, and he has no information regarding any inspiration used to create him. He first appears in Ring X Mama Volume 1 Chapter 4: Round 4.
After Ryoma has convinced Tiger Cat to rejoined Team Gigamax and Saeko congratulate him by the river, he appears along side Saeko. He compliments Ryoma for his excellent manager skills. He tells Saeko that he will not get involved with his ex-wife's business and that he will remain contact with Saeko. Later on, he appears with Iwakura at the Sumeragi mansion on the anniversary of Beauty Panther's death. He shares his disgust with Iwakura when Darkness Aoi appears. When Ryoma and his team arrive at the Sumeragi mansion for the holidays, Sanjo meets the team and requests Sanae to speak with him in private.