I will give simple and short details of this anime so it won't hurt the interest when someone is gonna watch it.
Neighbour, is an alien type people who were not born into Meeden (a.k.a. Earth). Who attack normal people to steal life energy (a.k.a. Trion). So in order to protect people of a hidden academy discover a technology which is basically inspired by Neighbours (Name Trigger). And one of our protagonists is one of the agent of that academy, border agent. Mikumo Osamu is the agent from Border who use to study in Mikado High School and he was keeping secret from his classmate that he is a border agent. Then one day he meets with Koga Yuma, who claims himself as Neighbour and after many things happened and Osamu and Yuma became friends. Osamu has a very close friend name Chika. With Yuma and Chika they made a team and aiming for being Rank A Agents.
