Gioca first appears disguised as a boy, but her true gender and her background as the descendant of the guardian in the Rangda mask are revealed by the Black Saints. Gioca is the only remaining member of the Death Queen Island Clan (デスクィーン島の一族 Desu Kwīn-tō no ichizoku?) as they were all murdered by Black Hound Yudo. She inadvertently involves herself in the crisis of the Black Saints by stealing Cancer Manigoldo's coin purse during one of her escapades. Later, she stealthily follows the Saints by tracking their Cosmo, as she reveals she possesses a marginal mastery of Cosmo, having awakened her own sometime ago. She is accompanied by her little pet monkey Tonto (トント Tonto?),Gioca is sought after by the Black Saints in order to force her to destroy the Rangda mask. Driven to the edge of desperation by Yudo, she awakens her Cosmo once again, knocking out Yudo momentarily.