 If you liked
Shingetsutan Tsukihime
|
 ...then you might like
Hitsuji no Uta
|
These two are similar mostly because they both deal with individuals who have rather odd \"latent\" abilities (dealing with vampiric practices sort of) until arriving into their high school lives. They both also deal with blood sucking environments (vampires again). Each series has a dark undertone (Tsukihime is somewhat on the lighter side though).
Horror romance anime with vampire characters. Progression occurs very slowly, but ultimately there is some substantial character development. Both also have cool aesthetics, always with dark or greyish colors, and are well-directed. Brother-sister relationships are a theme in both.