Its been years so there might be mistakes. I played it on android, It was unfinished when I played it and it looked like anime 3dcg. The first scene I can remember is the brother (probably can't remember if it was Incest) peeing on the toilet while his his sister was taking a bath next to him with curtains of course. At some point his sister visited his room at night asking to help her on some game, then they were on the spooning with a few inches a part with the brother having a boner while teaching his sister, then they got caught by their mom. That's all I can remember.
