I was expecting quite a bit from this game seeing as how it is a highly rated NTR game (4.5 stars with 40 votes and 31 pages of comments at the time of me writing this). With that said, I do believe it let me down.
Hentai: The main girl and her sister not only have excellent designs but they both have H-scenes, a massive tick in the game's favor. The hentai itself ranges from very well made to not very good, no real standard of quality. I'm a bit disappointed that there is only one threesome scene with the two sisters, especially with how involved the sister is in the story. There are also quite a bit of recycled scenes and, on top of that, there's not really too many to begin with as it relates to the amount of time you'll need to put in to unlock them. One major detractor is that there are no sex scenes for the vanilla routes, but I'll touch on that later.
Story: The non-NTR endings are rather decent, honestly they're better written than the NTR endings. The NTR endings are incredibly generic and quite bland as all six NTR routes are not only heavily trope heavy for the genre, but relies far too much on forceful NTR in order to drive the story forward. Another major issue is that Ryouka goes from love-struck pure maiden to giga whore in the span of a week and is incredibly quick to give up her own values and desires, which in turn destroys her entire character. It's incoherent and anti-immersive. I've played many NTR games and this one is by-far one of the worst cases of the main-girl doing a complete and quick 180 for no reason other than to drive the NTR plot. It's like the reverse of The Curse of Kubel.
Other: In order to unlock all scenes and all endings you must play this game at least seven times (and it's not a short game if you're reading the story) or pray that RNG is in your favor. That's absurd, especially since the NTR stories are rather poorly written and the hentai isn't really worth the effort. It leaves this game feeling incredibly grindy and drawn out. On top of that, the RNG aspect makes you want to have to follow only one route at a time in case RNG is not in your favor, thus causing you to have wasted your time by the end. If you want her to sleep with every man in town in one run, you're likely not getting a true ending. I also feel this game leans a bit too much into the genuine romance aspect for the girl, which is a bit much. There's also no h-scene for either of the two vanilla routes. At that point I ask, why bother including those routes? Yeah its an NTR game, but you included heavy non-NTR story and aspects. The MC is completely empty headed, I do not care that he is getting NTR'd nor do I care if he wins the girl. He is the worst character in a game of badly written characters. Also, are you telling me that every single male in this universe is a dark-skinned ugly bastard? Because that's what this game is entirely about. If you're into that, fair enough. But for me, it's way too much. I was expecting one or two of the guys to be ugly bastards, not every single one.
Gameplay: A nice phone feature and tracking feature to see what the girl's up to, though it becomes incredibly repetitive. The trials to unlock her memories are quite easy, you just have to grind in order to get the materials needed to get through them. Gameplay is nothing special, but not horrible. Minor point though, it was fun finding and "playing" the games that are references to other well known hentai games.
The game is by far not perfect, but if you're willing to slog through the story and are fine with every h-scene being an ugly bastard one, go for it. If you just plan on skipping the story for the H-scenes, then I'd suggest maybe spending your time on a different game. A solid 3/5, anything higher is too much.