Sola (2007)
Plot
High school boy falls for a mysterious girl he meets on the street. Turns out she's a powerful and almost immortal creature damned to walk the Earth alone forever. She is being hunted, so the boy invites her to hide at his place.
Where to watch Sola?
Sola is an anime show created by Naoki Yanagi.
Sola is currently streaming for free (ad-supported) on Tubi TV.