I recommend "Dress up quickly and play the male god in your arms." The female protagonist of this short story, Baili Qing, is an otaku with a stupid system. Her mission is to travel through various planes to break up the love line. There is a chapter about a brother-sister relationship. There are some faint feelings between the female protagonist and the male protagonist. The female protagonist is a smart and indifferent girl. After the male protagonist learned that the female protagonist liked him, he tried his best to pursue the female protagonist and got her heart. I hope you like this fairy's recommendation. Muah ~😗