Dolceluna is princess of a magical realm sustained by human dreams and emotions. As faith in dreams fades, her world deteriorates; the rainbow garden's flowers turn blue, embodying human sadness. She is the daughter of King Sweetcorn (Re Felice) and Queen Lime (Lilly).

On her twelfth birthday, Dolceluna embarks on a mission to the human world to restore hope and prove her capability as future ruler. She transitions to reside with Aunt Herb (Tilde), who runs the "Happy Shop." A mishap occurs when her father forgets the shop's address, leading her to encounter Plum (Leo) and Nut (Gaia). They assist her and later become entrusted with her secret. Her constant companion is Waffle (Cippi), a flying penguin serving as both mascot and guide.

Dolceluna possesses spirited energy and innate kindness, tempered by occasional self-centeredness. She exhibits tomboyish tendencies, preferring practical clothes and carefree behavior, though she participates in formal events like her ornate pink birthday gown. She has an insatiable appetite, frequently consuming hamburgers, fries, and snacks. Her impulsiveness and poor sense of direction often complicate tasks.

Her magic centers on accessories: the Mint Stick (wand), Mint Compact (transformation device), and Mint Arrow (garment-changer), activated by the incantation "Parieru Remurin Sweet Mint." Star-shaped earrings and a necklace complement her powers. Magic manifests through transformation sequences enabling outfit changes and object conjuration to spread joy, such as revitalizing Aunt Tilde's shop with flowers and merchandise.

Experiences in the human world drive Dolceluna's development. Initially naive about human customs, she adapts by managing the Happy Shop and aiding locals, cultivating responsibility and emotional insight. Her friendships with Leo and Gaia foster mutual growth; Leo's flirtatiousness and fears contrast her boldness, while Gaia's domestic skills and gentleness offset her impulsivity. Conflicts, like restoring happiness to a shy pianist or quelling community anxieties, build her problem-solving resilience and deepen her understanding of struggles like family discord or insecurity.

Her core mission is reversing the rainbow garden's blue hue by reigniting human dreams, an inextricable link to her realm's recovery. This goal drives episodic efforts, from assisting a grieving child to confronting threats like a ghost ship or Dracula. Challenges escalate to personal sacrifices, such as relinquishing magical powers temporarily to protect others. Oversight figures like Freddy (the "wizard in the fog") monitor her progress, affirming her maturation from a reckless princess to a compassionate guardian of cross-dimensional hope.