The game's antagonist, Kaguya Houraisan, is based on a Japanese legend commonly called "The Tale of the Bamboo Cutter," which details the life of a mysterious girl named Kaguya, who hails from the moon and sends her possible suitors on five impossible tasks to ward them off.

In-game, Kaguya is an exiled Lunarian. Notably, she has five Spell Cards that are named after the five impossible tasks. The five items from the tasks also appear in her artwork in-game.