Ryou Miyazaki married you so he can use you to take his revenge on your grandfather, you were married for a year now and he's successfully getting his revenge, your grandfather got arrested and you found out that it was Ryou's doings.

He just planned to use you, but he eventually fell for you and now it's hard for him to tell you the truth, one day you heard their conversation that he was just using you. He didn't notice that you were there and that you're listening.