Ryo Asahina forms one half of the Platonic Twins alongside his twin sister Suzu. They share an intense psychic connection forged after surviving a lethal mountain blizzard, where Ryo accepted Ohga's offer of a Kaiser Stone to save Suzu. This pact fused them into a cyborg-like entity in exchange for eternal servitude.

In their combined "Platonic Twins" form—officially nicknamed the Suspicious-Looking White Giant—Ryo comprises the head, shoulders, and legs, while Suzu forms the exposed-armed torso. Ryo fiercely protects Suzu during combat, believing their mutual love amplifies their strength despite romantic undertones challenging their "platonic" label.

Ryo exhibits passionate protectiveness toward Suzu, mirroring her devotion to him. Minor conflicts arise from their differing tastes in idol culture, which neither approves of for the other.

During Ohga's test of Isato Kaiza, the twins overwhelm Isato and Kash until Isato's Kaiser Stone weakens. When Isato's ally Karin intervenes, the twins electrocute her, triggering Isato's rage. He directs a lethal attack at Suzu, but Ryo intercepts it, sacrificing himself. Fatally wounded, Ryo dies in Suzu's arms. Grief-stricken, Suzu vows revenge and requests a new Kaiser Stone from Ohga.

Ryo's death catalyzes Suzu's transformation into "Platonic Slave." She battles Isato and Kash relentlessly but collapses from emotional agony when Isato refuses to counterattack. Her solitary power strains her, manifesting as physical pain from the Kaiser Stone until Kash stabilizes her.