"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! Our hero Osamu Mikumo may not be the best agent, but along with his Neighbor friend Yuma, he'll do whatever it takes to defend life on Earth as we kno it. Should Border admit a Neighbor into its ranks? Jin and Arashiyama Squad think so, and they clash against headquarters' top agents to preserve Yuma's right to enlist"--Page 4 of cover.