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.

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 he’ll do whatever it takes to defend life on Earth as we know it.When Osamu meets a feisty humanoid Neighbor named Yuma, everything that he thinks is right is turned on its head. Can the two natural enemies ever beco...

It’s the final day of the battle simulation exercises, and the formerly superior Ninomiya’s Squad 8 is in decline now that others are exploiting the weaknesses of Chika’s units. While Chika grows more and more frustrated, Ninomiya himself is keeping tight-lipped about the whole thing… That night, it all comes to a head when an irritated Ema confronts Ninomiya!

Day six of the Sealed Environment Phase commences, and Wakamura’s Squad relies on Hyuse’s knowledge to complete their assignments. Meanwhile, Suwa’s Squad takes on the day’s sim battles using Osamu’s strategy, but all of their moves end up being countered! Will they be able to bounce back in the rankings?

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 know it. Ever since they met, Osamu has protected the feisty Neighbor’s identity, but he’s about to get a rude awakening that Border has ...

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.

Yuma's Neighbor identity revealed, the Tamakoma branch safeguards Yuma, Osamu and Chika by recruiting them to their group of powerhouses and eccentrics. But Border headquarters wants Yuma’s Black Trigger badly enough to send agents from its top three squads to steal it!

With only seven seconds left until the crossroads, time is running out. Black Triggers face off as Miwa activates Fujin to bring the invasion to an end. But can everyone really escape the worst possible future?

Border headquarters is abuzz with gossip about talented new rookies Yuma and Chika. But it’s Osamu who attracts the most attention when an A-Rank agent challenges him to a duel. Then it’s Yuma’s turn to fight when another A-Rank agent challenges him! Plus there’s that meeting with Border’s top brass that they just got called to… Is there such a thing as too grand an introduction?

With less than 16 minutes left until the crossroads Jin predicted, the endgame looms. Will Osamu make it back to HQ in time to save the cubified Chika?

Humanoid Neighbors from another dimension enter the battlefield for the first time! With strange Triggers that defy explanation, they make quick work of even top Border agents until the agents start to fight smart. Can Border turn the tide of battle in time to save Mikado City?

It’s a Neighbor invasion! Trion soldiers swarm Mikado City, wreaking havoc and capturing isolated Border agents. When the sinister humanoid Neighbors orchestrating the attack target Chika for her massive Trion, Osamu may be the only one who can save her! But can a B-Rank agent compete against the surprising power of this new alien foe?