Shiki Tohno, an ordinary high school student starts another day of school. At school he learns of a recent murder with the victim having what seems to be vampire marks on their neck. He also has a strange encounter with a girl named Ciel, whom seems to be his friend but he has no memory of her. On his way home from school he has a strange day dream of killing a girl he sees. He then wakes up in his sister's mansion, where he was moving to that day. He meets the two maids and they tell him he can't go out past 7 pm. Bored, he sneaks out to go get some magazines. On his way back he finds a man collapsed with teeth marks on his neck, he also sees a girl with a sword who looks like Ciel. Confused, he passes out. He awakes the next morning in his room again. He goes to read the newspaper but finds nothing on the incident, leading him to believe it was a dream. His sister also discovers about how he snuck out. On his way to school he runs into the mysterious girl that he had the dream of kil

The woman introduces herself as Arcueid, and tells Shiki that he killed her. Confused and scared, he runs off. When he gets to school he realizes he has finally lost her. At lunch he asks Ciel if that was her last night with the sword... Offended, she says no. After school Shiki walks home with his female friend Satsuki, she reminds him how he once helped her out in middle school and that he will always be there for her when she needs him. Its her birthday and she goes off to have dinner at a fancy hotel with her parents. Shiki gets to the mansion and finds Arcueid waiting for him at the gate. Scared again, he runs off. She corners him in an alley. She reveals to him she is a vampire princess. Just then they are attacked by black wolves. She defeats them and takes him back to her hotel. She reveals to him how she came back to life and is weakened now thanks to him. Just then a mysterious man enters the hotel and unleashes several of the black wolves. Arcueid and Shiki go to escape but

Shiki awakes the next day in Arcueid's hotel room once again. She wants to see what these lines he sees is all about. He shows her on a chair by cutting the lines he sees and making it fall apart. He explains to her when he breaks the lines the thing or person is destined to fall apart, thus how he killed her so easily. However, when he puts his glasses back on, he can nolonger see the lines. Back at the mansion, Shiki's sister Akiha is worried about him. Shiki's classmate Arihiko calls to see why he wasn't in school just to learn he hasn't come home either. That night Shiki and Arcueid decide to team up to kill Nero. Shiki hides behind a tree as Nero appears and attacks Arcueid. Shiki tries to sneak up on Nero but he doesn't fall for it. He creates more of his black wolves and seems to have Arcueid defeated when all the sudden Shiki breaks through and gets a single cut in with his knife. This is all it takes for Nero to fall apart due to his life lines being cut. Shiki collapses exhau

Shiki comes crawling home after his battle with Nero. When he awakes in the morning his sister is extremely angered with him for dissapearing and not telling her he would be gone. But due to what he did he can't reveal where he was. He goes to school and gets confronted by Ciel and his friends. He assures them that everything is ok, but Ciel seems oddly concerned with the whole story. That night, Akiha throws a ""coming home"" party for Shiki and they share a special dinner. Later the two maids, Kohaku and Hisui tell Shiki how Akiha was very worried over him and she loves him dearly. Feeling bad he goes over to talk to her. They take a trip down memory lane on when they were kids and how they'd play. Shiki remembers a young boy playing with them but Akiha has no recolection of it. That night when Shiki goes to bed he has a dream that Arcueid crawls through his window to bite his neck. The next morning after he arrives at school he comes to find by looking out the window, Arcueid is on th

Shiki finds out that Arcueid has came to school to visit Shiki while basking in the attentions of his classmates. Ciel is unhappy of Arcueid's presence. A misunderstanding happens between Shiki and his friends. Shiki finds out from arcueid the Nero was just an ordinary assassin. So they plan on going hunting that night. In the manor, Shiki tries to sneak out of the house. Hisui gave Shiki the house and gate keys so that it would be easier for him to get home. Arcueid tells him that the real vampire she was after was named Roa. Then while walking, they encounter their first acolyte.

Akiha reprimands Shiki in her own little way when he is late to breakfast and refuses food. She tells him that taking care of himself is more important than his studies, and they can hire a tutor if need be. Hisui confides that Akiha doesn't know he leaves the house every night....

Shiki and Akiha bid farewell to their maids and head out to meet Shiki's friends. Akiha is still pissed that she caught him sneaking in at 2AM the night before. He apologizes and she asks him not to do it again. If he continues to disobey, she will install a security camera... Shiki and Akiha join Inui, Ciel and Yumitsuka at the train station at 10AM. Akiha and Ciel take an immediate disliking to each other, and soon, Shiki confronts Akiha about her rude behavior to his friends. He then thinks back to the night before with Arc. She had asked him on a date, but he replied that he already had plans...

The news reports that last night, a girl named Andou Tomomi was found dead. She had left her friends around 7PM to ride the ferris wheel. Shiki is worried about Akiha, who has been acting strange since last night. He asks if it was something Ciel said. She gets up angrily but then faints. Shiki wants to call a doctor, but the maids remind him that Akiha hates doctors and assure him that she will recover with rest. Shiki is still concerned. Why would she get sick so suddenly? Kohaku explains that this often happens whenever Akiha suffers mental anguish. Shiki realizes that he is the cause and decides to stay with her tonight...

Shiki recovers from his attack under Akiha's watchful eye. He dreams of being a small boy who awakens to find himself along. He hears a woman's voice calling his name from beyond the trees. He follows it and finds a number of dead bodies that lie massacred. Above, the woman calling him lies impaled on a tree. She drops her knife and he picks it up. As she dies, her blood drips onto his face. Horrified, the young boy picks up the knife and starts slicing at the tree in frustration.

Shiki is still affected by the memory of the wound he received from his father and is unable to even face his sister Akiha; however he’s shocked when Arcueid arrives unexpectedly and very angry. Shiki ends up going out on a date with Arcueid to make it up to her and they both find out new things about each other. They both end up going to his school as Arcuied wants to know more about his everyday life, when all of a suddenly she gets upset when he mentions Ciel. Shiki tries to find out what’s wrong but they are interrupted by a series of events.

Arcueid flees, and Ciel explains that Arcueid was the White Princess of the True Ancestors until Roa offered her a rose with blood that caused her to undergo a cycle where she would awaken for brief periods to kill Roa and then go to sleep once more. Shiki goes to follow Arcueid but comes upon Roa and Akiha. Roa begins to overwhelm the two until Ciel arrives, but she is dispatched. Roa retreats and Ciel regenerates her wound. At home, Shiki finds that he was adopted, and that he swapped places with the actual Shiki Tohno after he went berserk. Shiki then goes to Arcueid, and makes love to her in her apartment. When he awakens, he finds a note with the words "Bye, Bye" on them.

After reading the farewell note Arcueid left for him, Shiki immediately heads out to look for her; however Ciel tries to stop him. Knowing that absolutely nothing is going to stop him from looking for Arcueid, Ciel decides to help him look for Arcueid who happens to be fighting Roa at the school.