Bloodletter by littleblackcat
Rin is a vampire hunter tasked with ridding the world of the dangerous creatures. His latest assignment is proving to be more complicated than most. Nitori seems to be the exact opposite of everything he's known about vampires. He blends in well at school, he doesn't cause any problems and he doesn't even drink human blood. Rin actually likes the vampire. Will he be able to carry out his assignment or will he help his little kouhai avoid certain death?
Even though it's still in its early stages, I'm really fascinated with this story. Seeing Rin struggle to reconcile is feelings for his friend and his duty as a vampire hunter is quite interesting. Nitori, as always, is a little ball of sunshine that makes you want to hug him. Definitely give this story a try!