My Sister Is a Big Star

What? My sister, who is lazy, pretty, and enjoys torturing me, was born to different parents than me? What? She wanted to be a big star, but fortunately my system added a perfect human-shaped golden finger. Help her clear all obstacles! What? My parents asked me to help solve her single problem, and I'm still single! Why don't you miss me? I don't want to do it, I protest, it's miserable enough to be a younger brother! Still think I'm my brother-in-law?