Hi. Read this five, probably, years ago and I cannot find it.
Naruto is a vampire and he has to find his mate. Every full moon he suffers from severe pain because he can't find his true mate. I remember he hates blood. Tsunade was bitten because Naruto got drunk(?) and actually thought she was young and hot. Hinata is also part of his entourage. I think Tenten or Sakura was with him too. He found Sasuke, a young prince (well, he was rich), as a child and bite him, thereby leaving his mark on him. He promised to come back and tasked Hinata to look after Sasuke. When he came back, he found that Sasuke hated him and so he set about trying to get the boy to fall in love with him. Itachi, in this story, is an ok brother. No angst stuff going on. Kakashi, I believe, is Sasuke's tutor. Sasuke hated him because he thought Naruto had forgotten about him since they met when he was eight(?) and their second meeting was when he was seventeen or eighteen. Eventually Naruto dies, Hinata manage to convince Sasuke to go to him. Sasuke confess his love, Naruto wakes up and they leave together.
It's crazy that I can remember all this, but I have NO idea what the story is named or who the author is. Whether it was completed or not, I can't remember. Might've read it on fanfic.net. There wasn't any smute so I don't believe it was rated M, but then again I can't remember if it was completed so maybe it did have some further down. Had a few chapters, but can be wrong.