Koyomi Araragi spent his last year of high school helping girls in his town resolve various supernatural afflictions. But now Araragi has departed for university, leaving his friends to fend for themselves against new problems and curses that plague them. Yotsugi Ononoki, once a human corpse and now a living doll, takes residence in Araragi's home, keeping watch over his sister Tsukihi, a girl harboring a mystical secret of her own. As part of her duties, Yotsugi fills Araragi's vacated role as occult expert, assisting others in town with their issues.