One day, a portal is suddenly opened in Mikado City linking it to a different world. Monsters known as Neighbors started pouring out from it and starts attacking the inhabitants of the city. Everyone is terrified of these monsters because Earth’s weapons does not affect them in any way. However, a mysterious defense agency called “Border” is established to combat against these petrifying enemies. Ever since then, Neighbors are contained from disrupting the Mikado City residents which now they are living their daily life as usual. After four and a half years since the portal opened for the very first time, a humanoid Neighbor enters Mikado City where he encounters a Border agent identified as Osamu Mikumo.
Type: TV (50 episodes x 23 minutes)
Studio: Toei Animation
Aired: Oct 5, 2014 to Oct 4, 2015
Watch online: Crunchyroll