reencounter

Has a short lived, hidden identity element.
Both MC & ML reincarnate, keeping their previous memories up until their deaths.
Now living in another "story" where MC knows ML fall in love with someone else, she keeps her distance. That is until he personally hires her w/o knowing its her, to make a potion that would alleviate his situation.

We see when they first meet: MC is the daughter of a rich noble while ML is a music teacher. He initially plans to use her to rise in ranks until MC's dad commits suicide and she looses all her wealth. Years later, they meet again when MC is now a humble teacher and he's wealthy businessman.