Catching Hitagi Senjougahara when she falls down the stairs reveals something inexplicable to Koyomi Araragi: his classmate is unnaturally weightless. She protests his involvement, but he insists on helping and turns to Meme Oshino, whose intervention once saved him from vampirism.
A third-year high school student, Araragi has returned to being human after a vampire attack, though superhuman healing and enhanced vision remain. With support from his friend and class president, Tsubasa Hanekawa, he tries to maintain an ordinary student life. Senjougahara's condition brings him back to Oshino, a strange man staying in an abandoned building. Across encounters involving demons and gods, Araragi works to help people afflicted by supernatural conditions.
