Miyu is the main protagonist of Vampire Princess Miyu. She and her Western Shinma companion, Larva (not to be confused with the vampire species of the same name) hunt down and dispatch stray Shinma.
Exactly what "Shinma" are is uncertain because the OVA and TV series have different and incompatible linages for Miyu. In the OVA her mother was a vampire and her father a human and she was born post-WWII but in the TV series her father was a Shinma guardian and her mother was human with her born during the pre-WWII Empire of Japan era (1868-1931) and used the name Yamano Miyu to mingle with the humans.
The translation of the Shinma is no help as it means "god-demon".
While she must feed on blood to survive she chooses her victims very carefully as they must willing giver her their blood. If this is granted the blood drain will result in them entering an endless dream state where their greatest desires are granted in their dreams. It is uncertain how often she must feed.