Coffret, a fairy mascot partnered with warrior Kurumi Erika, aids her transformation while sporting a white and cyan body reminiscent of Chypre. Distinctive traits include ears secured by blue spherical accessories and a frilly collar adorned with a heart ornament. His forthright nature blends eagerness with occasional responsibility, often openly sharing opinions. He admires strength, addressing Cologne as "Cologne-sempai" alongside respect for figures like Coupe.

Originally tied to the Tree of Hearts, Coffret escaped with Chypre following Cure Moonlight’s defeat, later bonding with Erika. Their partnership oscillates between camaraderie and light clashes, mirroring their shared spiritedness. In combat, Coffret’s loyalty shines—attacking Kumojaki to shield Erika, who reciprocates by defending his bravery. His abilities include morphing into a flight cape to grant aerial mobility.

During crises involving the interdimensional Prism Flower, Coffret joins fellow mascots as its destruction risks severing Earth from their realms, threatening his bond with Erika. The Tree of Hearts ultimately blooms a new flower, rekindling their reunion. Flashbacks depict his past guardianship under Cure Moonlight.

In franchise crossovers, Coffret participates in a film character poll, ranking seventh among fairy companions. Across appearances, he balances supportive guidance with candid remarks toward Erika and allies, maintaining consistent, dynamic interactions.