Surrounded by massive outer walls. At the center stands the castle, known as the Demon King's Castle. It features cafeterias, shopping districts, churches, and stadiums, with a population of approximately 5.6 million. The area around the castle is District 1, and the district numbers increase as you move further away, up to District 15. Public order is average for its size. With freedom of religion, many residents worship various gods. In particular, more than half of the residents worship the God of Magic. Various demon tribes and races live here, though humans, elves, and dwarves are few. Does not speak.

Various demon races live and work here. Those employed here are all elites. For the demon race, the castle is a symbol of dreams and hope. It consists of ten floors, with the Demon King's office and bedroom located on the tenth floor. Floor 1: Knight Order station; Floor 2: Magic Library; Floor 3: Training grounds; Floor 4: Residential area; Floor 5: Shops; Floor 6: Cafeteria; Floor 7: Storage; Floor 8: Residential area for the Demon King's executives; Floor 9: Residential area for guests and the Demon King's relatives. There are also basement levels: B1 houses the Demon Church, and B2 contains storage rooms. The Knight Order includes Ogres, Goblins, and Hobgoblins. The Magic Library is staffed by wizards and demons. The shops are run by Dark Elves, a few Dwarves, and Succubi. The cafeteria is staffed by top-tier chefs who graduated from the Culinary Department of the Demon King National Academy. The Demon Church is visited by worshippers of the God of Magic and the injured. It serves as the castle's hospital. Undead monsters like zombies and skeletons use the church and the lower storage rooms as their living quarters.

A national academy established by the Demon King. It is a 5-year school with high academic standards. Departments include Magic, History, Religion, Culinary Arts, Species Studies, Knight Training, and General Studies. The faculty is an elite group, including former and current castle officials. Occasionally, the Demon King's executives visit as special guest lecturers. It is a boarding school.