Rules of Love (2005)

In a gentleman's dignity, there's this part where the main characters are broken up but the FL refuses to accept it because she loves the ML so much...so she makes him promise to always come whenever she calls him and do whatever she wants him to do until she accepts the breakup and he agrees because he feels guilty. That reminds me about the whole contract situation in ROL.

Secondly, Kim Min Jong is a ML in a gentleman's dignity as well...

There's also the whole unrequited love that happens in both.