A prequel to the video game by the same name.

The video takes place in the year 2065, six years before the events of the videogame. In the video, three wielders of the "divine weapons" from the Fenrir Far East branch, an elite military task force, arrive at a military operation against the powerful creatures called Aragami. One of the three, Souma, is a protagonist in the videogame.

(Source: Anime News Network)