Shinou (眞王) was the first Maou of Shin Makoku. Shinou lived 4000 years ago, the son of a King of an unknown country. He left his home country and, with help of the Daikenja, he united all Mazoku in fight against Soushu. Then he formed Shin Makoku and became the first Maou. After his death, his soul resides in the Shrine of Shinou and he tells the priestesses there the names of each successive Maou.
While he was still in his old country his eldest brother died. When he left the country he had three older brothers, an older sister, and two younger sisters. His father liked to play around with many women so he also had many illegitimate children. The Daikenja was probably a child from one of his affairs, making Shinou and Daikenja half brothers.
Shinou was the first King of Shin Makoku. After his death, his soul watches over the lands of Shin Makoku, and priestess such as Ulrike can communicate with him in a limited fashion, one they call "hearing His Majesty's voice". Murata also appears to be able to communicate with him, and is often seen scolding him for meddling in Shin Makoku's affairs.
Differences in anime
4000 years ago, Shinou sealed Soshu into four boxes, which became known as the "Four Forbidden Boxes". However, while part of the Soshu was sealed in the boxes, a small part of the Soshu infected Shinou to the extent where his right arm seemed slightly decayed. Shinou knew that the Soshu would eventually take over his mind and body completely, so Shinou came up with a plan along with his Great Sage to completely eradicate the Soshu in the future. This involved sealing the Soshu with a pure soul, and destroying it. This soul turned out to be Shinou, but Yuuri manages to eradicate the Soshu without harming Shinou, earning Yuuri the title of the greatest Maou. Shinou commented that he was glad he chose Yuuri as the Maou.
- In Chapter 77, Murata Ken said that Shinou and Daikenja weren't exactly "best friends". This could be a hint of the fact that they probably were half-brothers, or in any case, lovers.
- He was one of the very few Mazoku who made pact with all of the elements (earth, water, air and fire).