The show is set in Cross Academy, a school with a day class of normal humans and a night class of vampires. It is upto Yuki Cross and Zero Kiryu as prefects (and the only students who know the truth about the night class) to keep the two classes seperate.
The show choses to concentrate more on the emotional and drama side of the situation than on any action scenes. Although this works for a few episodes the formula of Zero trying to live a normal life whilst turning into a vampire and Yuki pining over Kaname quickly becomes very dull. Although I have to say the end of the second season is avast improvement. It is justa shame that it took so long to get there.