Gate: Jieitai Kanochi nite, Kaku Tatakaeri

A massive gate suddenly appears in Ginza, releasing medieval soldiers and fantasy creatures into Tokyo. Japan Self-Defense Forces officer Youji Itami helps civilians escape the attack, and the invasion is eventually repelled as Japan secures the mysterious passage.

3 months later, Itami leads a reconnaissance team into the "Special Region" beyond the gate, a world of an empire, dragons, elves, and other peoples. Their task is to gather information and build relationships that might prevent another war, but the presence of a modern military immediately changes the region's balance of power. Itami must treat the people he meets as more than strategic assets, because one political mistake could ignite conflict on both sides of the gate.