Coffret, a fairy from the Great Tree of Hearts, sports a white and cyan form adorned with a blue frilly collar and a silver heart pendant. Outward-facing ears, secured by blue spherical accessories, frame his face. His speech peppers every sentence with "-desu," complementing his playful, mischievous demeanor as a self-styled younger sibling to partner Kurumi Erika. Though earnest and duty-bound, he veers into bluntness or impatience when Erika shirks responsibilities or favors leisure over their mission.

Fleeing the Tree of Hearts alongside Chypre after Cure Moonlight’s defeat, he seeks new Pretty Cures to safeguard their home. After briefly staying with Tsubomi, he bonds with Erika, mentoring her transformation into Cure Marine. Their similar temperaments spark frequent squabbles, yet mutual trust gradually tempers their rapport. Coffret openly idolizes senior fairies—addressing Coupe as "Coupe-sama" and honoring Cologne as "Cologne-sempai."

In combat, he summons Erika’s Pretty Cure Heart Seed, rallies her morale, and morphs into a flight cape for aerial maneuvers. His bravery surfaces in crises, such as lunging at Kumojaki to shield Cure Marine during their final clash—a defiant act against dismissals of his strength, cementing his loyalty as Erika fiercely vouches for his valor. He aids in purifying Desertrians, harvesting Heart Seeds to rejuvenate the Tree of Hearts.

Temporarily sheltered by Tsukikage Yuri before her power loss, Coffret later reflects on Cure Moonlight’s fate, convinced Cologne’s survival might have altered it. Past insecurities over Erika’s regard once drove him to steal her Flower Tact, though reconciliation deepens their bond.

Appearing in *Heartcatch Pretty Cure!* and the *Tropical-Rouge! Pretty Cure* crossover film, Coffret remains Erika’s steadfast partner. His journey balances growing courage and responsibility in pivotal moments with an enduringly spirited, outspoken nature.