Kara no Kyoukai: Satsujin Kousatsu (Zen)

March, 1995: Mikiya Kokutou meets a girl who has a mysterious gaze and falls in love with her. That April, he's reunited with her at his high school entrance ceremony. The girl's name is Shiki Ryougi. Meanwhile, the city has been rattled by a series of bizarre murders. There are no known links between victims, and the motive is unclear. An astonishing secret awaits Mikiya, but he doesn't find out until three years later...
(Source: Aniplex USA)