The Uninvited Guest appears within the narrative of Egu Island following the disappearance of the songstress End of the World, an event that sparks widespread anger, doubt, and anxiety among the populace. Amidst this volatile atmosphere, the character becomes involved in the fractious conflicts and schemes collectively known as the "Licking War" or "Great Licking War," where various factions pursue objectives related to the vanished diva and the legendary Egumi Legacy treasure. The specific motivations driving the Uninvited Guest's actions during this conflict are not detailed. No background story, origin details, or personal history for the character are provided. Similarly, information regarding the character's development, evolution, or significant changes throughout the series or any official media extensions is absent. While the character's personality traits and internal complexities are not explicitly described, sources allude to a potential sense of conflict or contradiction associated with the role, without elaboration. The extent of the Uninvited Guest's direct involvement in locating End of the World or securing the Egumi Legacy remains undefined. Information concerning the character's appearance or relevance to media beyond the single season of the anime television series, such as movies, OVAs, spin-offs, or the original card game, is not present.