伪物语是伪物的物语(伪即不真实，不成熟，虚伪的)。历和女友战场原是伪物；历的两个妹妹火怜和月火是伪物；欺诈师贝木等也是伪物。而相对的，羽川是个非常强大的真物。伪物语中的怪异都与历的妹妹扯上了关系，引发了一系列的事件。

The story centers on Koyomi Araragi, a third year high school student who has recently survived a vampire attack, and finds himself mixed up with all kinds of apparitions: gods, ghosts, myths, and spirits.

One day, Koyomi Araragi encounters the horrifying vampire, Kiss-shot Acerola-orion Heart-under-blade A.K.A. the "King of Apparitions." He saves the fatally wounded Kiss-shot by offering his blood at the expense of his own life as a human. Now Koyomi has to face the vampire hunters to retrieve Kiss-shot’s limbs which were taken by these hunters...