One day in Japan, in the Ginza district, magical Gates open—through which troops from the Empire located in a parallel world invade the country. In the world on the other side of the Gates live fantastic beings such as elves and dragons, and some of them can be extremely dangerous. However, the development of the Empire is overall at the level of the Middle Ages—so Japan not only manages to repel the invasion, but also takes control of the Gates. Now all countries are interested in using them and getting their hands on the resources of a world that has not yet been touched by modern civilization. Despite everything, Japan tries to hold onto its monopoly. After capturing the Gates, several units are formed to study the parallel world and establish friendly relations with the local population. The leader of one of these units becomes the main character—Itami Yōji. (c)