Cosmo (コスモ Kosumo) is the Cosmos Fiend (宇う宙ちゅうの魔ま人じん Uchū no Majin) and is one of Quanxi's girlfriends and represents the fear of omniscience and gaining knowledge of everything in the universe. On the surface, Cosmo doesn't exhibit many emotions aside from her usual smiling, happy-go-lucky attitude. She doesn't speak except for repeating the word "Halloween" and, like the rest of Quanxi's fiends, follows Quanxi around and is in constant love with her and under her command.