World Trigger (Unknown)

A mysterious Gate opens above Mikado City and allows beings from another world to enter, leading to the creation of Border, an organization that uses Trigger technology to defend humanity. Years later, trainee Osamu Mikumo meets new student Yuma Kuga, who hides the fact that he is a Neighbor from the other side of the Gate. They are soon joined by Chika Amatori, who is searching for people lost in that other world. From joining Border to a massive Neighbor invasion and the beginning of the B-Rank Wars, the three learn that deciding who the enemy truly is can sometimes be harder than defeating one.