Appearing exclusively in Episode 14 of the "World Fairy Tale Series" adaptation of Lewis Carroll's "Alice in Wonderland," the character "Re di cuori" (King of Hearts) inhabits the Queen of Hearts' court within this fairy tale segment. The series faithfully adapts the original source material, making minimal alterations for its half-hour format. Consequently, the King of Hearts fulfills his traditional role as the queen's consort, frequently attempting to temper her impulsive decrees and her frequent execution demands. His demeanor remains consistently submissive and anxious in the queen's presence.

As one of 26 distinct, standalone fairy tales adapted in the anthology series with no overarching continuity, the King of Hearts exists solely within this specific "Alice in Wonderland" episode. The documented information provides no additional background story, character development, expanded role, or unique character evolution beyond the established Wonderland narrative. He does not appear in other episodes, seasons, movies, OVAs, or spin-offs within the series. Canonical sources offer no further details on his origins, motivations, or relationships outside the Wonderland context.