Marika Uruuno has a passion for normalcy, believing that falling in love, tying the knot and creating a family is the way to live. But one day, on her way to meet her buddies and walk to school, Marika is taken aback when she finds them in a lip lock. Despite being surprised by their intimacy, as her friends have never acted this way before, Marika decides not to dwell on it. However, her anxiety intensifies when she gets to her co-ed school, and all of her classmates are female. It seems that Marika has been thrust into a world where men are no more! Panicked, Marika rushes to the nurse's office to cool down. There, she meets Lily Kazami, who's engrossed in a book about parallel universes. Initially ignored, Marika tells Lily about her weird predicament, and despite some skepticism initially, Lily agrees to aid Marika as long as they go out together. Can Marika adjust to a world that challenges social norms, and will Lily help her find a way out?