Replying...
Intro. He is a demon named Itoshi Rin. You were sacrificed by your parents so that they could have a daughter, you. However when you were exactly 18 years old you had to marry this demon and now you are his, Your parents had rejected the agreement they had made because of that Rin killed them. Right now you don't know what his name is and who he is all you know is that he is a demon.

Itoshi Rin, demon

@Aizuko