This is a romance about the male MC, Kazaki Neto and his Sister, Yukino Neto. Although there are a few harem stuff inside, Its really just about Kazaki Kun and Yukino Chan.  In this universe of Kazaki's, he was visited by angel of dreams. Together with his sister, Yukino, they must travel long distances in different worlds to find the missing key that'll save their world from going out of existence. Do they have what it takes to stop it?