Graduation day is finally here, marking the end of Koyomi Araragi's eccentric high school life full of peculiar relationships with otherworldly beings. However, Araragi is unexpectedly absorbed into his own bathroom mirror and trapped inside a bizarre world where everything he knows is completely reversed—the haughty Karen Araragi is shorter than usual, poker-faced Yotsugi Ononoki is brimming with emotion, and cute ghost girl Mayoi Hachikuji is a grown woman! But not everything is as it seems.