One day, a gate to another world opened in Mikado City. Invaders from another dimension, referred to thereafter as Neighbors, overran the area around the gate, leaving the city gripped by fear. However, a mysterious group suddenly appeared and repelled the Neighbors. This Border Defense Agency independently researches Neighbor technology and fights to protect this world. In a short time, they managed to build an enormous base and prepare a defensive system against the Neighbors. it's been four years since then.
Source: Crunchyroll. Will be replaced by a unique synopsis written by Anime-Planet and updated tags.
FIRST EPISODE IMPRESSION OF WORLD TRIGGER!
Story: "Toriger...on"-and so it begins!..invaders from another world(nothing new*1 :c)..suddenly some years later there´s an advance..um..fighting..thingie so people can live in more peacly..?(still nothing new..)... an exchange stundent(c´mon..?)ahahahah at least he´s a kawaii shota..bullies ganging up on megane-kun and... read more
I'm currently on episode 6 and its damn good. I really dont understand why it's rated 3/5 stars, try it. You'll like it read more