Female lead dates person because she feels indebted to them

Any where the female lead only dates the male lead at first because she's indebted to him in some way? Male lead doesn't know and is in love with her. She's in love with the second male lead. The male lead finds out, but then she realizes she loves the male lead and they truly get together.

OR

She's only dating the second lead because she's in debted to him. She's in love with the male lead and in the end gets together with him.

So in both cases, she ends up with the male lead.

Once Upon a Time... In My Heart - Karn La Krang Neung…Nai Hua Jai (2016) maybe not too much as you want, but there is that she got with the second male lead becuase she in debted to him for a short time.