Snow Sakura. I think people tend to recommend the same VNs over and over. Now I will recommend something, which I have not seen being recommended at all. I feel it's a bit lost to history, which is a shame because it's actually a good one. The VN is about a guy whose parents goes overseas and he is sent to live with his uncle and his daughter (the cousin heroine). They live in a closed onsen hotel, meaning they have their own private onsen in the backyard. This naturally makes it a natural