One day in the 21st century, a gate opened in the middle of the Ginza district of Tokyo. Out of the gate poured soldiers and strange creatures, and they soon made Ginza look like an image of hell. The gate apparently connected Japan to another world, a world with a militant empire and many supernatural creatures. The Japanese Self-Defense Force decided to send a small group, led by a soldier who's also an otaku, into the other world on a reconnaissance mission. They're meant to learn what they can about the empire (and its plans), the world, and the people. They're hardly in the world yet, though, when they come across a village destroyed by a giant fire-breathing dragon. The only survivor is an unconscious elven girl they find hidden in a well. Now they feel like they must warn the nearby towns about the dragon, and do what they can to help. On the way, they'll meet more magical, female companions, and learn more about this dangerous new world. (Source: MangaHelpers)

In the year 20XX, a mysterious gate to another world suddenly opens in Tokyo's Ginza district. From beyond it pour invading armies and monstrous creatures from a fantasy realm. Japan's Self-Defense Forces repel the attack-and push forward through the gate into the unknown territory on the other side. Among the soldiers sent to investigate is Yoji Itami, a 33-year-old otaku officer who is anything but a typical soldier. Leading his unit into the newly discovered world, he sets out to scout nearby villages and assess the situation beyond the gate. What awaits them is not only danger... but the sight of fantastical races and beautiful girls straight out of a dream. Thus begins the unprecedented encounter between modern military force and a medieval fantasy world, where guns meet dragons and diplomacy clashes with magic. (Source: Hanashi Media)