It's called Cinderella. I've seen it. The ending is so depressing. The man later found out that his sister didn't really like him, so he broke up with her and fell in love with her. So I live with my sister. Her sister couldn't bear to commit suicide because that man broke up with her, but she didn't die. She was found and rescued by her sister. But my sister broke up with that man because she felt that both her sisters were unhappy with him. My sister lost her memory and became gentle. This man ended up with no one. According to the ending hint, my sister should be with her old boyfriend.