Mutou Mitsuki is summoned from Japan to another world by the king of Grisarika Kingdom who measures him for a power called Pure Concept. Mitsuki is surprised when the king summons another, a girl from Japan, while he is thrown out of the castle. He meets a priestess called Menou who explains people from Japan with powers called Lost Ones have been summoned throughout history, so many in fact that Japanese culture took over the world. Exploring his power Mitsuki discovers his Pure Concept is highly destructive in nature...