Ryo Nishihara is a main character in the series, working as a professional wrestler for the fictional Berserk company. She transitioned from modeling to wrestling to prove her worth and establish herself as a top industry competitor. As part of the wrestling idol group Sweet Diva, she blends wrestling performances with idol activities to broaden their fanbase. Within the group, Ryo serves as the powerhouse, recognized for her exceptional physical strength and agility in the ring. Her fiercely competitive nature often sparks conflicts with other members.

Driven by intense pride and determination, Ryo relentlessly pushes her physical limits to hone her skills and showcase her superiority. Her ultimate ambition is to win the world championship title, cementing her status as the globe's strongest wrestler. This relentless drive fuels her actions and training, epitomized by her declaration: "I won't lose to anyone when it comes to desire!" Ryo has brown hair.