Eartbroken Stories

I'm think about a story about two lovers from different worlds and time periods with different social status and different race the boy is human and the girl is a reaper . The story is said in the girls perspective as she reminiscence about her time with the boy she lived with. they met when they were 8 the girl was a princess who was shunned by the royal family . then she meets a boy who came to her world from our world . they meet live together trying to help the boy find his way back home .but because he is human they must hide his existence as a human .