King Donuts, a blue dragon monarch, governs the Doughnut Kingdom east of the Palmier Kingdom as one of the Four Rulers protecting the realms encircling Palmier. Safeguarding the Rose Garden Key—a vital artifact for entering the Cure Rose Garden—he awakens from a dormant Palmin state, immediately chastising Coco and Nuts for their perceived shortcomings as Palmier’s leaders, his imperious demeanor masking a sense of duty. Temporarily joining the Pretty Cure to recuperate, he clashes with Syrup, disparaging the team’s lax discipline while aiding them in combat by summoning bursts of bright blue light from his hands to immobilize foes. Though prideful, he gradually softens, advising Rin on duty prioritization and subtly showing care for allies.

Upon regaining strength, he departs, leaving a calling card as a farewell token. Years later, in *Kibou no Chikara ~Otona Pretty Cure '23~*, he resurfaces, seeking aid to address ecological disasters plaguing his kingdom—deforestation, water scarcity—and relying on Palmier’s support for recovery, underscoring his pragmatic struggles as a ruler.

Designed after the Seiryu (Azure Dragon) of Chinese myth, his dessert-themed name aligns with the Four Rulers’ motif. His speech, marked by the suffix “~dona,” mirrors others in the franchise. Interactions with the Pretty Cure and Palmier’s citizens trace his evolution from aloof critic to collaborative ally, blending regal hauteur with a deepened commitment to his subjects’ welfare and interkingdom alliances.