One day, Shiki Tohno, a high school student meets a beaufitul lady in a park and out of pure instinct, he dismembers her in 17 pieces with his pocket knive. The day after that, he meets her again in a park and she\'s in one piece. Her name: Arcueid Brunestud, the princess of the Shinzo. She tells Shiki that she needs his power in order to defeat Roa and the Shito a.k.a the vampires that sucks blood from the victim. Arcueid says to him that she hates blood but Shiki has difficulty believing that. He agrees to help her hunt the at night. Meanwhile, his sister Akiha worries about him leaving the mansion at night so she tells the maids Kohaku and Husui (they are twin sisters) to lock the gate at night but Husui betrays Akiha and gives the gate key to Shiki so he can sneak out during the night. When following Arcueid at night, Shiki begins to realizes that he is not human because once he takes his glasses off, he sees \'\' the lines \'\' in order to cut the vampires in their weak spot. Little by little, the mystery begins to accumulate for Shiki because he think his sister is hiding something from him about his past and the tohno family and he tries to find out the real identity of Arcueid and then, a mysterious women appears and tells Shiki to stay away from Arcueid. Will Shiki find the truth about the Tohno family ??? Will he and Arcueid beats the Shito vampires and finding the key to resolve all the mystery that surrounds him ???