Mofurun began as a light brown teddy bear, a gift from Asahina Mirai's grandmother during her infancy. This plush companion came to life and gained speech when Mirai first transformed alongside Izayoi Liko, adopting a verbal tic ending sentences with "~mofu". Initially without discernible abilities, Mofurun later developed sensitivity to detecting Linkle Stones through a distinctive "sweet smell" and became essential to the transformation process for Cure Miracle and Cure Magical, requiring physical contact with her paws.

Physically, Mofurun features blue eyes, a white stomach, star-adorned ears, heart-patterned paws, and a fuchsia bow with a jewel compact. The character's gender identity was intentionally non-binary, described by staff as "simply Mofurun," a concept reinforced by Cure Mofurun's androgynous design featuring shorts instead of skirts. In the film *Witchy Pretty Cure! The Movie: Wonderous! Cure Mofurun*, exposure to the Linkle Stone Mofurun triggered Mofurun's transformation into Cure Mofurun. This humanoid form possesses auburn curly hair, retains bear-like eyes and ears, and wears witch-inspired attire. It later accessed elemental variants: Ruby Style (fire), Sapphire Style (water), Topaz Style (electricity), and Heartful Style (featuring wings and enhanced accessories).

Mofurun's personality blends curiosity, gluttony, and emotional vulnerability during crises with responsible traits, demonstrated through caretaking of Ha-chan and academic support for Mirai and Liko. Core relationships include a sisterly bond with Mirai, mutual respect with Liko forged through shared magical experiences, and protective guardianship of Ha-chan. Despite Chikurun's initial betrayal as a spy, Mofurun's persistent kindness eventually forged a genuine friendship.

In *Precure Super Stars!*, Mofurun appears alongside the Witchy Pretty Cure team during their confrontation with the truth-distorting monster Usobakka. During the sequel series *Witchy Pretty Cure!! ~Mirai Days~*, Mofurun continues residing with Mirai as she attends university in the No Magic Realm, maintaining their lifelong companionship.

The character facilitates powerful group attacks like the Rainbow Carriage summoning and Extreme Rainbow, later unlocking the Heartful Rainbow purification technique as Cure Mofurun. Mofurun's narrative includes arcs such as temporary disillusionment about usefulness, a central role in a Cinderella-inspired story as "Mofuruderella," and reconciliation with the reformed antagonist Kumata despite prior betrayal.