Duke Creme de Brûlée holds the ducal title within the Sweetsland Kingdom. He schemes to seize control of the entire kingdom while simultaneously pursuing Princess Mana's affections. His secret agenda involves overthrowing the current rulers. To achieve this, he deploys agents like the macaron Sweetspets for espionage, specifically targeting Ruby and her group. The Duke orchestrates the launch of Gumimin, a male Sweetspet with deliberately erased memories, toward Sweetsland intending to disrupt Princess Mana's seventh birthday. This memory manipulation directly causes Gumimin's initial amnesia and confusion. The Duke maintains a persistent interest in Gumimin, later revealed to stem from Gumimin's status as a legendary Sweetspet possessing unique abilities vital to Sweetsland's stability. Others frequently misname him due to difficulty pronouncing "Creme de Brûlée," leading him to insist subordinates call him "sire." His methods involve deploying traps and indirect strategies, which often backfire, frequently ensnaring his own macaron assistants. His actions escalate to indirectly triggering a crisis when Gumimin transforms into a destructive force consuming Sweetsland's structures. His design motif is inspired by gummy candy. The narrative positions him as the instigator of the central conflict, exploiting magical elements and manipulation to further his goals of usurpation and winning Princess Mana's hand.