Midori is a normal high school student until one day, the new girl, Mayumi, arrives and befriends Midori, telling her that she can travel between worlds and is a kind of refugee—that she indeed arrived on Midori’s world after her own and several other realities were destroyed. Odd things start to happen, and Midori begins to slip back and forth between multiple Earths. On one world, Midori is told that she’s a mental patient, dreaming up these other realities. Is Midori just insane? What role does Mayumi have in all this? Or is there more to reality than we think?