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.

Another invasion is under way, and alien country Galopoula plans to infiltrate Border HQ. The A-Rank and B-Rank agents have their hands full on the ground, but the commotion outside is only a distraction! A handful of humanoid Neighbors manage to sneak their way into Border’s away ship hangar, and it’s up to the top four Attackers to stop them!