Riiya is an orphaned wolfboy raised by his grandfather in a cottage on Mochimochi Mountain near Seravy's residence. He shares a deep childhood bond with Chacha, serving as her loyal companion and protector during their adventures. His family heritage connects him to a giant wolf, granting him inherent physical strength and triggering occasional transformations when he experiences strong emotions like anger or protective instincts.

He studies at Urara Magic School alongside Chacha and Shiine, where his lack of magical aptitude contrasts sharply with his physical prowess. A central dynamic is his rivalry with Shiine for Chacha's affection, a competition Chacha largely overlooks. This rivalry intensifies when Shiine joins their group, establishing a persistent love triangle.

A key development occurs when an accident triggers amnesia; rescued by the mermaid Marin, who becomes infatuated with him, this incident temporarily strains his relationship with Chacha as Marin actively interferes. Despite these external romantic pressures, his loyalty to Chacha remains steadfast.

Riiya wields one of the three essential magical items—a bell. Combined with Chacha's pendant and Shiine's staff, it enables Chacha's transformation into the Magical Princess to combat threats. His role within this trio is vital, emphasizing their teamwork and mutual reliance.

Later narrative arcs delve into his family background, uncovering revelations about his mother and grandfather. His grandfather occasionally visits, demonstrating their familial ties and contributing comedic or plot-driving moments, such as consuming school lunches.

Throughout the series, his character evolves from a straightforward protector into a more complex figure navigating friendship, rivalry, and familial identity, while his core traits of bravery and devotion remain constant.