Trigger, On! Collision between two worlds had wrecked havoc in a region in Japan, Mikadoshi. In no time havoc was made everywhere and it all started with just a black hole coming out of nowhere and monsters from another parallel dimension. These monsters are called the Naver and are called by the residents of Mikadoshi “neighbors”, the residents the other parallel dimension. Now an organization called Border has been set up to fight off these monsters, after a while people began to trust the Border and headquarters was set up. Now, Border had their own arsenal of weapons, these weapons are specifically designed to fight against the Naver. These weapons are called Triggers, they operate based on Trion. As they say, a picture speaks a thousand words. Just look at the manga cutscenes that explain about the relationship between the Trigger and the Trion. After that, we will talk about the characters.
Alright now on to the characters. Currently there are two characters that are to be recognized, one human and one Naver. Both of them are the protagonists and the human is called Mikumo Osamu and the Naver is called Kuga Yuuma. Kuga Yuuma appeared one day into this world and bumped into the strong-willed justice holder, Mikumo Osamu. Thus their story begun. By the way, Yuuma is the short one that has white hair and Osamu is the one that’s taller and is a four-eyes.