From MangaHelpers :
High school student Misumi Makoto is called into a fantasy world by the god Tsukuyomi, in order to be a hero. However, powerful others in this world aren't as thrilled to have him there, and they kick him to the edge of the world just as Tsukuyomi declares that he must leave Makoto to find his own way. Now it's up to Makoto to find his own way.