Ryōna is one of the twin younger sisters of Ryōki. She initially attended Gessen Girls' Academy with her sister Ryōbi before transferring to Hebijo Clandestine Girls' Academy. This transfer occurred after the death of their elder sister Ryōki, which they blamed on Miyabi. Enrolling at Hebijo allowed them to gain Miyabi's trust and execute their plan to assassinate her for revenge.

Ryōna possesses short blonde hair and heterochromatic eyes: green in the left and blue in the right. She favors a winged princess outfit featuring a white tutu with triangular patterns, stockings, platform boots, and accessory wings, accentuating her curvy figure. In combat, she wields dual pistols freestyle: an incendiary pistol firing scorching bullets and a cryogenic pistol firing freezing bullets. She integrates dance and ice-skating movements into her attacks, enabling her to glide across surfaces. Her personality exhibits extreme masochism; she openly displays her body, seeks physical punishment, and disturbs others with unabashed discussions of her preferences. Despite this, she displays kindness and reluctance to fight unless necessary, such as hesitating to kill Miyabi after learning the truth about Ryōki's death and showing compassion during battles.

Within *Shinovi Versus*, Ryōna and Ryōbi infiltrate Hebijo for revenge. Ryōna targets Imu during the assassination attempt, but Murasaki intercepts the bullet meant for Imu. This triggers Imu's "Root of Calamity" power, defeating Ryōna and Ryōbi. Reconciliation follows after Rin clarifies Ryōki's death circumstances. The OVA *Festival Eve Full of Swimsuits* shows Ryōna during a spa resort truce. When Kuroku enemies attack and transformation abilities are blocked, most girls activate "Super Frantic Mode," destroying their clothing for enhanced power. Exhausted, Ryōna drinks an experimental growth drug from Haruka's bag, becoming a giant. She crushes enemies while likening the experience to being pricked by needles. To revert her, the girls attack her, causing her to sweat out the drug. This results in an explosion that defeats the enemies and returns her to normal size.

In *Estival Versus*, Ryōna's storyline focuses on whimsical masochistic desires, including an obsession with becoming a "tempura udon bowl" to be consumed. She participates in the "Kagura Millennium Festival," where interactions with the resurrected Ryōki address themes of grief and closure. Ryōna accepts Ryōki's presence more readily than her conflicted sister. During *Peach Beach Splash*, Ryōna expresses frustration over the lack of physical pain in water gun battles. She approaches characters like Mirai, Katsuragi, Miyabi, Yozakura, and Yumi, begging to be harmed, particularly requesting breast slaps. Yumi placates her with shaved ice laced with a headache-inducing ingredient. Ryōna embraces this as suffering, repeatedly requesting more while hailing Yumi as her "master."

Her character development across media consistently balances masochistic humor with underlying loyalty and vulnerability, particularly in her dedication to her sisters and reluctant participation in violence. Her actions in the OVA and later games reinforce her pursuit of pain as a core trait while maintaining her role within Hebijo team dynamics.