Hirose Goushi has a huge sister complex. So huge, he moves from his home town to Tokyo to attend Myouzen University in order to escape it!
Three years later, Goushi's little sister Noa shows up and informs him that she's taking the Myouzen University entrance exam and that she will be moving in if she passed. Little does Goushi know, she has a similarly large (if not larger) brother complex.