Ryo Asahina forms one half of the twin duo known as the Platonic Twins alongside his sister, Suzu Asahina. They share a profound psychic connection, constantly sensing each other's presence, location, and thoughts. This bond originated during a near-fatal mountain blizzard where they were the only survivors. As Suzu froze to death, Ryo accepted an offer from Ohga for a Kaiser Stone to save her, granting them a fused combat form in exchange for eternal loyalty.

In their combined Kaiser form, nicknamed the "Suspicious-Looking White Giant," Ryo constitutes the arms, shoulders, legs, and head, while Suzu forms the central torso. This fusion channels their mutual devotion into combat strength. Ryo is deeply protective of Suzu and passionate about their relationship, contrasting with Suzu's slightly more aggressive demeanor. They share interests in different idol music, with Ryo owning a treasured Shaia CD. Ryo specifically dislikes cats and sweets.

During a mission for Ohga to test the hero Isato Kaiza (Gowcaizer), the twins confronted Isato and Kash Gyustan (Hellstinger). When Isato unleashed a powerful attack targeting Suzu, Ryo intervened to shield her, sacrificing his life. His death drove Suzu to seek a solitary Kaiser Stone for vengeance against Isato, despite Ohga's warnings about the risks of fighting without their shared form.

Ryo's background includes being rescued from abandonment by people who rejected their relationship, solidifying his commitment to Suzu and Ohga. Their fusion ability and reliance on each other in battle underscore their narrative significance as sub-bosses in Ohga's hierarchy, with their combined form referencing themes of forbidden sibling romance and evoking henshin hero tropes.