Nanairo Reincarnation gets a very weird 5 stars from me. As much as I have mixed feelings about it, I still can't think of giving it anything else.
The VN has great art, and excellent sex CGs. The artist really knows how to put eroticism into every detail. However, the sex scenes aren't paced or written to give you an amazing nut. What they are is written to be fun and interesting and continue to build the characters relationships. So the super hot art is almost at odds with the writing but it's way too good for me to not want.
Then you have the writing in general. While it does rely on really dumb, aggravating anime tropes it never managed to piss me off enough to take me out of the story. And there are enough genuinely good moments and well-executed ideas to make the vast majority of it enjoyable. Hell, some character moments had an outright fantastic amount of nuance and depth to them. All in all, it comes across as something penned by a talented writer that actually has a life who had to fulfill a quota of shitty harem anime tropes under pain of death.
Still, not everything bad is the fault of anime tropes. There are a number of pivotal emotional moments that are clearly designed to drive the audience to tears that just... don't. This is largely because the emotional weight relies on the blandest character in the VN. They would be inoffensive if not for the importance rested on them, but the writer putting what are supposed to be the biggest scenes in the story on their shoulders doesn't work out.
What really stops my complaints from taking away a star is the production values. The art is not just great, but consistently great in every area and it's accompanied by solid programming with a good suite of modern features as well as great voice acting. Any time a flaw threatens to pull you out, there's enough quality on display that it sucks you right back in. So definitely check it out. It won't be the best VN you've read or an amazing fap, but you'll still be glad you did.