Book/ Character Info

What happens when a strange light suddenly transports a group of both US Marines and US Army Soldiers to the future in Japan but when Demons and Monsters lurk about the place. The country and city they will be a challenging test for the group. What will happen and who will they meet?
(BTW I know that Taimanin Asagi are very lacking in both Fanfiction and Watt pad stories so this is my version of one.)