She is Violent Rose, a wrestler of Team Gigamax. She is Japanese despite her blonde hair and a married woman.
She has connections to how Team Gigamax fall apart. No information is available yet.
Saeko Shimazu is a main character of the Ring X Mama series created by Jouji Manabe. It originally began serialization in Takeshobo's NaMaiki! magazine. He has no information regarding any inspiration used to create him.
Her first appearance was in Ring X Mama Volume 1 CH. 1 "Round 1".
She is a married woman. Unlike the other ladies, she is not a promiscuous woman. Though she did had sex with Ryoma to take out some frustrations over her roles as a good wife and wrestler in chapter 14.
She first appears when she calls Sanae, Justice. After Ryoma becomes manager, she asks Ryoma to seek out Tiger Cat and ask her to come back to the team.