Chapter 1: Triple Canopy

In August 20XX, a portal to a parallel world known as the "Gate", suddenly appeared in Ginza, Tokyo where monsters and human warriors wearing ancient armor poured out of the portal, killing everyone in their way and trying to claim the area as their own and now a PMC team and Japanese Self Defense Forces launches a counter attack to stop them...with allies in the other world.

Gate: Thus The JSDF Fought There! Fanfic