O Mordomo de Preto (2014)

Both movies are about a noble lady & a butler. Both movies are very similar.................................................

Both FLs are human and MLs are a demon who are bound in some way to the FL. In both, there are mysterious crimes taking place.

Good romance. You have *bo-shan's* and main caretaker instead of butler. Shes gonna suffer for accepting to be a babysitter to BIG (adult) baby's. Worth of watching X"DDD

Both are about a person making a contract with a demon, selling his soul, in return for working with, protected by the demon. Both are based on famous manga.............................

Mizushima Hiro plays a butler in both. Kuroshitsuji is a movie and more dark than Me-chan no Shitsuji but both are good and if you liked his acting as a butler you should give the other one a try too.

Both MLs are powerful supernatural beings who make a contract/deal with the FL that is supposed to result in destruction (of the world vs. her soul).

Both are fantasy movies set in Medieval Europe. Both are based on famous manga................................................................................................................

Both movies are about demon MLs who have a contract of some sort with the human FL who is much stronger than she first appears.