Inversion Impulse

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