Ryōna is a first-year student at Hebijo Clandestine Girls' Academy, transferring alongside her twin sister Ryōbi from Gessen Girls' Academy. This move followed the death of their older sister Ryōki, killed during a mission involving Miyabi. Convinced Miyabi caused Ryōki's demise, Ryōna and Ryōbi enrolled at Hebijo to infiltrate Miyabi's trust and assassinate her for revenge. Their plan culminated in an attempt to kill Miyabi and her teammate Imu. This failed when Murasaki intercepted the bullet meant for Imu, triggering Imu's transformation into the Root of Calamity. The incident forced Ryōna and Ryōbi to face the consequences of their actions, leading to reconciliation with the Hebijo team after the full truth about Ryōki's death emerged. Ryōna exhibits a pronounced masochistic personality, actively seeking physical punishment and verbal scolding. She frequently displays her breasts without hesitation and openly discusses her masochistic tendencies, often unsettling others. Despite this, she demonstrates compassion and reluctance toward unnecessary violence. She expressed remorse during fights with Murasaki and Yozakura and hesitated to kill Miyabi after learning the full circumstances of Ryōki's death. Her loyalty to Ryōbi compelled her to proceed with the assassination once Ryōbi initiated it. In non-combat scenarios, Ryōna's eccentricities include expressing a desire to transform into a bowl of tempura udon to be consumed, citing the pleasure of being "fried like a shrimp" as an extension of her masochism. During Peach Beach Splash, her craving for physical pain intensified. She approached characters like Mirai, Katsuragi, Miyabi, and Yozakura requesting punishment, though most refused. Her persistence resulted in Yumi providing headache-inducing shaved ice, which Ryōna embraced as satisfying torment. Physically, Ryōna has short blonde hair and heterochromatic eyes—green on the left and blue on the right. She typically wears a white ballerina-style tutu with triangular patterns, held by thin threads that minimally cover her bust, white stockings with gold trim, knee-high platform boots, angelic wings, and a silver tiara. Her combat attire consistently emphasizes her curvy physique. In combat, Ryōna wields dual pistols fused at the hilts—one incendiary, one cryogenic. She employs a freestyle, dance-like shooting posture, incorporating ice-skating movements to glide across surfaces like sand, rock, or walls. Her graceful acrobatics combine with elemental effects; shots from both pistols generate explosive ice crystals, reflecting her playful yet lethal efficiency.