Gate: Thus The Marines Fought There

On an otherwise peaceful summer day in Tokyo, the tranquility of Ginza is shattered by a brutal attack, leaving thousands dead in the streets. In the aftermath, the question arises: who is responsible, and how should they be held to account? Initially believed to be a terrorist assault, the truth emerges that the assailants are legionnaires, Orks, and dragons emerging from a mysterious gate that has opened in Ginza, revealing a portal to a parallel world filled with fantastical creatures. With news of the incident spreading worldwide, Japan accepts assistance from the United States, who dispatch a brigade seized Marine Expeditionary Unit of 3,000 Marines aboard the USS Albright to aid in the response.

DISCLAIMER: I do not own Gate nor the images I'm using. I'm writing this story based off of the Anime, I never read the manga or the novel so don't throw with rocks at me if I change a bit of the lore