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.

After the recent Neighbor invasion, thirty-two agents went missing and Osamu, Yuma and Chika, a.k.a. Tamakoma-2 Squad, intend to go get those people back. But first they need to rank up through the Rank Wars. Having won their first match, they must now prepare to face off against Arafune and Suwa squads in the middle B-Rank Wars.