Yomi

Yomi (黄泉 Yomi): or better known as "Yomi-no-kuni" (黄泉の国 "Yellow springs/wells") was the dark underworld located in the underground which is featured in the crossover season Gonzo☆Pretty Cure!, also a place for the main antagonists, the Guardians of Yomi such as Leontes Van De Montague, Aion, Maria, Cain Nightroad and Issa Shuzen. Yomi is the world of being represent death in Shinto mythology. The place first appeared in the episode 1 of the crossover season.