Lit. "True Demon Kingdom"; the kingdom of the Mazoku of which Yuuri is king, founded by the Shinou after he defeated the Soushu. Divided into the terrories under direct control of the Maou and those ruled by the Ten Aristocratic Houses. Its human-shaped population is about 50 million, but also has a great variety of other races, such as the Kotsuhizoku.

The name "Shinma Kingdom" is actually an abbreviation; its true name is "the kingdom founded by the great Shinou and the powerful, wise, and courageous Mazoku who—ah, it must not be forgotten are said to be the origin of everything in the world—defeated the Soushu and his army to their eternal glory" (偉大なる眞王とその民たる魔族に栄えあれああ世界の全ては我等魔族から始まったのだということを忘れてはならない創主たちをも打ち倒した力と叡知と勇気をもって魔族の繁栄は永遠なるものなり王国).