Kiel is an original character created for the anime adaptation. He appears early in the narrative as one of the princes encountered by the protagonist, joining their journey alongside Navi and Prince Avi. Unlike other princes confined within rings that require awakening, Kiel is freely active within the Dream World, suggesting a distinct status or origin. He initially possesses no memory of being a prince.

Kiel displays a charming and easygoing personality, forming a contrast with Avi's more serious nature. This difference leads to recurring interpersonal friction between the two princes during their travels. His presence marks him as a member of the core group dedicated to confronting the dream-eating entities endangering their world.

Beyond the anime, Kiel features prominently in official stage play adaptations. A dedicated performance titled "Side Kiel" explores his storyline, positioning him as a central figure alongside Avi within this medium. Merchandise tied to the anime, such as Blu-ray disc releases, included exclusive in-game content focused on Kiel, reinforcing his significance within the franchise.