World Trigger, Vol. 4

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.

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. After a brutal fight against his friends and peers, Jin makes an unimaginable sacrifice to put an end to the hostility and protect Yuma’s future at Border.