Destroy thy Neighbor! A gate to another dimension has burst open, and invincible monsters called Neighbors invade Earth. Osamu Mikumo may not be the best among the elite warriors who co-opt other-dimensional technology to fight back, but along with his Neighbor friend Yuma, he'll do whatever it takes to defend life on Earth as we know it.

Osamu successfully convinces Border HQ to allow Hyuse to join their squad, and now the moody Neighbor from Aftokrator must make his way up through the C-Rank Wars to officially become part of the team. Meanwhile, Tamakoma-2 gears up for another B-Rank Wars match against the analytical Oji Squad and the unconventional Ikoma Squad. How will Tamakoma-2 handle a squad that operates almost exactly like they do and another squad that doesn't even seem to care that there's a match going on?!