Oukoku Game

is a Japanese manga series written and illustrated by Sorase Haruyuki. The manga was serialized in the Dengeki Daioh magazine and published in Japan by ASCII Media Works under the Dengeki Comics NEXT imprint from September 2013.

Synopsis
At the end of Meiji Restoration, a girl saint was crucified and burnt alive under persecution.

A century later, Katori and six childhood friends are summoned to her world beyond the nirvana, where they receive the Great Commission: Build a kingdom, and make disciples of all nations.

At every midnight, each of them are randomly given a role out of King/Queen, Noble, and Peasants. As the lowly must obey a higher-up in the hierarchy, can they fight and defeat other nations to conquer the world--before infighting brought up by their own hidden desires breaks them apart?

(Source: Manga Updates)