World Trigger

Approximately four years ago, a gate to another world opened in Mikado City, and invaders called Neighbors appeared.

Border sees the Neighbor Yuma as an enemy… but Osamu is unable to view him as someone with hostile intentions, and trust begins to bloom between the two boys. Osamu finds himself caught between his own thoughts and the rules of the organization he belongs to, Border.

Combat-use Trion Soldiers attack when a gate opens in Osamu’s school just outside of the Forbidden Zone. Worried he’s not strong enough, Yuma tries to stop Osamu from fighting back, but Osamu’s determination to save the other students is limitless.

Osamu gets more trouble than credit when he claims to have defeated Trion Soldier Marmod. Really, he’s covering for the Neighbor, Yuma. Kitora, an A-rank Border Agent, is furious with Osamu for stepping out of line… But does she suspect the truth?

Kitora boldly jumps onto the back of Ilgar, a new type of Trion Soldier, while it’s mid-flight and bent on attacking the city below. Suddenly, Ilgar transforms, enters self-destruct mode and plummets toward its target. How will she escape now?!

Yuichi and Osamu's critical mission to investigate the abnormal gate puts a lot of pressure on Osamu. Meanwhile, Yuma follows Replica’s advice and conducts an investigation of his own. The next morning, Osamu and Yuichi have a fateful meeting with Yuma...

Osamu reaches out to Yuma and Replica. He and Chika learn some critical information about Neighbors from Yuma, but they're soon discovered by two A-Rank agents, Shuji and Yosuke; they're searching for a Neighbor in human form...

A-rank agents Shuji Miwa and Yosuke Yoneya make an assault on Yuma without even asking what happened. Osamu calls Jin to help.

With Shuji's squad singlehandedly defeated, the Border Agency's executives order Yuichi to defeat Yuma and recover the Black Trigger. Osamu worries about Yuichi's impending clash, while a secret hidden by Yuma is slowly exposed.

Jin encourages Yuma to join the Tamakoma branch. Yuma accepts it if he can team up with Osamu and Chika.

Osamu hears from Replica about why Yuma came to this world, and from Chika about her true feelings.

Osamu, Yuma and Chika decide to join Tamakoma branch to go to Neighbor world as A-rank agents of the expedition force. They go into rigorous training from Tamakoma First Unit in order to become A-rank agents.