Determined to protect life on Earth and the identity of his Neighbor friend Yuma from Border, Osamu Mikumo soon learns that Border has ways of finding the traitors in their midst.
Yuma's Neighbor idenity revealed, the Tamakoma branch safeguards him, Osamu and Chika by recruiting them to their group of powerhouses and eccentrics, but Border HQ wants Yuma's black trigger badily enough to send agents from its top three squads to steal it.
With the Earth under a constant threat from the Neighbors, invincible monsters from a different dimension, Border agent Osamu Mikumo, determined to protect the planet, finds his beliefs challenged when he meets the fiesty humanoid Neighbor Yuma.
