You thought your neighbors were bad...but at least they're not aliens trying to kill you!

Earth is under constant threat from Neighbors, invincible monsters from another dimension that destroy our way of life. At least we have the elite warriors of Border, who co-opt alien technology to fight back! Meet agent Osamu Mikumo, not the best, but along with his Neighbor friend Yuma, he’ll do whatever it takes to defend life on Earth as we know it.

With only seven seconds left until the crossroads, time is running out. Black Triggers face off as Miwa activates Fujin to bring the invasion to an end. But can everyone really escape the worst possible future?