Saya hails from Planet Norg, where she encounters protagonist Yuu during his investigation of a distress signal. Her heritage ties to the legendary Titanis—hero who banished the demon Morgan—though she is not directly descended from Titanis. She joins Yuu's core team with allies like Momo and Nyan, fighting Morgan's resurgence on Norg.

She remains pivotal in subsequent adventures, aiding Van's mission to rescue Princess Lara on Planet Idea. Her role transcends support as she confronts antagonist Galum across timelines, sustaining her presence in the core team through multiple conflicts.

In the OVA *Galaxy Cougar's Trap*, Saya operates as an established Cosmic Hunter alongside Yuu. Their partnership includes responding to distress signals—like one from ally Nyan—and battling space pirates such as Belga. The OVA reveals personal dimensions to their relationship, depicting a date interrupted by mission demands.

Saya's character arc features a recurring romantic subplot with Yuu, noted as "intertwined feelings" during Norg's conflict. This dynamic extends to missions like their joint operation on Planet Kazarin, where she volunteers to impersonate kidnapped Princess Sarria due to their resemblance. She conducts undercover investigations while Yuu searches for the princess, underscoring her commitment to high-risk roles within team objectives.