Ghost Hunt, Vampire Knight Recommendations
Both have mysterious atmosphere and are about supernatural events. Mai resemble Yuki, and Kazuya - Zero. Relations between them are also very similar.
Yuki and Mai do look alike. If you want an in depth angle of Mai and kazuya relationship, watch Vampire Knight, and you'll see what i mean.
Both animes are about supernatural beings, but with a few alienations. While Vampire Knight deals with the 'bad guys' (The Vampires) in main roles, Ghost Hunt is about chasing the 'bad guys' (in this case Ghosts, Demons, etc). Vampire Knight also deals with a Love Triangle while Ghost Hunt is about a normal relationship (that builds up a little slower and less obvious than on VK). Naru (from GH) is similar to Kaname/Zero in so far that he is also very mysterious and doesn't want people come too close to him.