In a part of Japan that was sealed away in another world around 1925 in which the technology stagnated since then, the Myara Protection Agency (sometimes called Hidenobu) located in Kumamoto city, who's job is to protect this world from any danger, suspects that something is up at the top of the Lunar Mansion Mountain. A weird magic scent is being perceived from the very top of the mountain. You are sent by Hidenobu to investigate about this mystery and maybe find a way to resolve it.
During this journey, you'll discover something terrifying and put you in the center of a vast and strange story.