(Drop)I want to be an extra character, but I can't!

Alfarie was bored with his life. He was then magically reincarnated into the magic world after an earthquake in his town. Once reincarnated, he vowed to live a happy life, doing all the things he never did. He realized that he had the same fate as the protagonist in the fantasy novel. However, he resisted that fate. Alfarie thinks of becoming an extra who helps the protagonist to realize his dreams. And that protagonist is his sister!