Manga by Jinho Ko.
It's Noh-A's first day at Amityville High School, and her reception is chilly to say the least. Brutal might be a better description! Decapitated but not dead (or is she??), Noh-A quickly realizes that nothing is as it appears at Amityville High where paranormal creatures battle for supremacy. Caught in the crossfire, Noh-A may have to rely on the unlikely (and possibly unreliable) aid of the most sinister student at Amityville... the deadly Jack Frost!