Marron is a Sweets Spirit specializing in chestnut-based confections, especially chestnut cream. She possesses a consistently haughty and self-important demeanor, believing no human is worthy of being her partner and preferring to stay in the Sweets Kingdom. This attitude causes frequent clashes with the equally proud spirit Chocolat, though they maintain an underlying friendship despite their arguments.

Her distinctive magic utensil is a fork, unlike the spoons carried by other Sweets Spirits. Intrigue sparks when Chocolat, Vanilla, Caramel, and Cafe mention encountering a human, Miya Koshiro, who shares Marron's condescending attitude. Marron admires Miya's extreme determination to achieve her goals at any cost and decides to form a partnership with her.

Physically, Marron appears childlike with light brown hair reaching past her hips and yellow eyes. Her design features wings, an apron, tights, ribbons, and a hair bow, consistent with typical Sweets Spirit aesthetics.