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.

One of Eirin Yagokoro's spell cards is called "Curse of the Heavens 'Apollo 13'," and is named after the famed Apollo 13 of NASA's space project, which had a critical malfunction and was sent back to Earth.

In the attack's description on Normal difficulty, it reads "13 is an unlucky number. Only Lunarians know the reason for its failure." It is revealed in later supplementary works that its failure was the result of Lunarian sabotage.

Keine Kamishirasawa, the boss of stage 3, has her spell cards themed on the history of the Emperor of Japan.