The official site of this upcoming series posted a 136 second trailer that features the opening.
The story revolves around a timid orphan named Mizumura who goes to a missionary school in Tokyo. His seemingly normal life changes when a beautiful half-human Romanian girl, named Lilith, who suddenly transferred into his school. Mizumura discovers that he is actually a vampire hunter and the successor of the Romyuarudo lineage.
Hmm, sounds like the classic Bleach shonen premise mixed with vampires? It'll be something to see.