Unexpectedly good. (As of chapter 39)I’m not a lover of “sis-con” or incest stories. Luckily this doesn’t look like one... so far. And I’m enjoying it.The siblings (not related by blood) seem to have a normal, semi-adversarial relationship. Teasing, fighting and taking advantage of each other when they can. Normal.MC is an average person with an outstanding sister. But he’s not bitter about it. He seems like a bit of a wimp at first, but he does have hidden talents. Even without the System (which is pretty annoying)Keeping in my library for now