A gate appears in Tokyo's Ginza district sometime in the 21st century. From the gate pours out monsters, knights from middle-age Europe, and other fantasy-like beings, and they kill many of the citizens of Tokyo. This event is known as the Ginza Incident.... more>>

The government sends a small group of soldiers from the Japanese Self-Defense Forces to the alternate world beyond the gate. Led by otaku soldier Yōji, they find that the villages in the world are being attacked by a dragon. An elf girl who is a survivor from the dragon's rampage joins the group in their travels across the dangerous new world. <<less

In the summer of 20XX, a "gate to another world'' suddenly appeared in Ginza, Tokyo. What came pouring in from inside was a mysterious army... more>> and a group of hideous monsters. They go around slaughtering people, and Ginza in broad daylight quickly turns into a hellscape. While everyone was helplessly thrown into confusion in this state of emergency, there was one man who was brave enough to move around. That man was Yohji Itami, an otaku Self-Defense Force officer who would later be called the "Hero of Nijubashi"! <<less