Setsuna Higashi, once the Labyrinth operative Eas, served as a cunning antagonist to the Precure, leveraging her alias "Setsuna" to infiltrate their ranks under orders from leader Moebius. Her calculated manipulation of Love Momozono and allies faltered as Love’s persistent kindness chipped at her hardened resolve, igniting a moral struggle. Mortally wounded by Moebius’s betrayal, she was reborn through the Akarun artifact as Cure Passion—a warrior embodying redemption. Her transformation manifested in armor-like attire and a guarded aesthetic, reflecting her rebirth from shadowed loyalty to a guardian of joy.

Joining the Fresh Precure team, she navigated guilt and Earth’s unfamiliar customs with quiet reserve, her social awkwardness contrasting with fierce combat prowess. Support from Love, Miki, and Inori anchored her growth, culminating in pivotal trials: facing a spectral echo of her past self and embracing camaraderie through dance.

In *Precure All Stars DX2: Kibō no Hikari—Rainbow Jewel o Mamore!*, Cure Passion united with fellow Precure to defend the Rainbow Jewel against Bottom, unleashing her *Happiness Hurricane*—a petal-strewn whirlwind purifying foes—amid battles against resurrected adversaries.

Her bonds deepened post-redemption: Love’s familial insistence housed her with the Momozonos, while Miki and Inori fostered trust through shared trials. Though guilt lingered, her resolve to shield others never wavered, extending even to former Labyrinth comrades like Westar, whom she sought to redeem rather than defeat.

Cure Passion’s visual identity—a garnet-trimmed tiara, red-black layered dress, and Passion Harp—set her apart. Evolutions like Cure Angel Passion and Rainbow Cure Passion wove angelic wings and golden motifs into her design, symbolizing unity and ascendant purpose. Her declaration, *“The scarlet heart is the proof of happiness. Freshly-ripened, Cure Passion!*” echoed her journey from fractured loyalty to unwavering hope.