Kyou Kara Maou!

Kyo Kara Maoh!, known in Japan as Kyō Kara Maō! , is a Japanese series of light novels written by Tomo Takabayashi and illustrated by Temari Matsumoto. It has been adapted into an anime series and a manga. The story follows the adventures of 15-year old Yuri Shibuya , an average baseball loving high school student, who suddenly discovers he is the king of demons in another world.

Kyo Kara Maoh! takes place in an alternate world that Yuri Shibuya travels to by coming in contact with water. There are many nations in the alternate world, however, the plot centers around the "Great Demon Kingdom" ( , True Mazoku Land). The people of the kingdom are Demons ( ). The Demon Tribe have the ability to make a pact with an element, and they can use Majutsu ( , Mazoku special discipline) which they can control with Maryoku ( Mazoku power?). In the English translation, both terms are rendered as "magic". Covenant Castle (also translated as Blood Pledge Castle), is in the capital of the Great Demon Kingdom. It is the residence of the Demon King (マ王 or Maoh?, Mazoku King). The culture in the Great Demon Kingdom is very different from the Japanese culture Yuri is accustomed to, and the differences make for some amusing mishaps with long ranging consequences, such as an accidental proposal of marriage. The Great Demon Kingdom shows many similarities to medieval Europe. For example, the pronunciations of the names (as well as several of the names themselves) and the indications of language in the Great Demon Kingdom are derived or transliterated from the German language. Also, Conrad gives Yuri his name, which he claims means "July" in the language of the Great Demon Kingdom. In German, July is "Juli" pronounced "Yu-lee". Due to the lack of distinction between the Western sounds of the letters L and R in the Japanese language, this is rendered in Japanese as "Yuri." A nickname used to make fun of him is "Shibuya Yuri Harajuku Furi" and he claims that Conrad is responsible for it. Also, it may be noted that the nobles of the kingdom are named using the traditional naming conventions of German nobility, using the preposition "von" in their surnames to denote their fiefdom, as in Günter von Christ and Wolfram von Bielefeld.

Source: http://en.wikipedia.org/wiki/Kyo_Kara_Maoh!