I watched an anime show a while back on Crackle, but I can't remember the name. It's not there anymore but I really enjoyed it.
It started out with a teenage prince and his servant running through the woods being chased by zombie like creatures. They came across a house where a beautiful woman lived and asked for shelter. They both fell in love with her. Then, they found out that she was an immortal, and a group of assassins were after her blood. She turned the prince into an immortal as well. When he woke up 1000 years in the future, he couldn't remember anything, but he went on a search for her.