Tsukimonogatari

Koyomi Araragi is diligently studying for his college entrance tests when he starts to notice something very odd: his reflection in a mirror no longer appears, a sign of a real vampire. He seeks the assistance of the human-like doll Yotsugi Ononoki and her master, the expert on eternal oddities Yozuru Kagenui, out of concern for the condition of his body. Yozuru recognizes what is wrong with him right away and offers him two options: either not use the vampire skills he learned from Shinobu Oshino, or permanently lose his humanity.