Up until 1/3 of this ~23 hour game I was ready to give it a 4 star, maybe even 5! After all, there's a lot to like it here and you can see it's a labor of love, but after grinding the other 2/3 (~15 hours) of the game I have to drop it to 3.
I'll echo what others have said here:
Art and scenario design is superb and character concept is very good there's no doubt about this. No deformed/ugly males, no blank faces! Main town and most scenarios are rich and very detailed.
Gameplay is ok..ehh...and so is the story, and that's where things start to fall apart.
Trying to be succint, I can only say the combat system is unbalanced and flawed by design. Most abilities are useless and cost too much to use, only the MP is actually useful. Itens are expensive. Fighting enemies doesn't give you xp (surely a bug???) only if you hit them from behind. There are too many dungeons, they are too long and they are not fun and engaging dungeons like some other "kunoichi" games. There's next to no H content in dungeons, which even made me wish this game had more battle molestation - something I abhore. Dungeons make about 70% of the game runtime.
Then there's the story. It's like the author decided to create the most basic "oni"shonen story ever, and I mean completely fucking vanilla. No surprises, no dramatic curves, no attempt at making it anything fresh. Literally everyone in this universe and the next knows your father has become a demon and you gotta fight him in the final dungeon, troubled enemies become allies and big bad dies because of its arrogance. On the other hand, it's not terrible, it offers a cohesive (if boring) narrative that could serve as the backdrop for developing Karin's sexual escapades. Could've. Which sadly takes us to the next point:
First, gotta say, the H content is pretty good --- for the extremely brief moment this games remembers it is an adult game.
Style-wise is incredible, but the pacing is simply terrible. It starts slow, which is fine but then in just one or two chapters it throws you into what is 90% of the game's H content. Most of the content is set in the main town (edo), that means most of the other towns have no content. There's very few (or none) new content as chapters go. If you burn through everything in the earlier chapters there's nothing to do except whore in edo during the night, which gets old after you see the same scenes over and over again. Even the support female cast have a sad participation in this game, only through a few, and I mean VERY few defeat rape scenes, which is a shame because all the female cast is pretty good.
Corruption is badly handled. The game doesn't give you the opportunity for a slow burn here: If you want to see h scenes you have to grab the protagonist by the neck and throw her into a brothel and/or sell her virginity to some old people just because. No, there's no "need money" plot here. She's also not sexually curious, so you are not given any narrative purpose to seek it. As expected, you have the usual binary states of sex scared and sex deranged. Basically, the adult content is built like a separate mechanic from the main game instead of woven into it.
The game simply doesn't give opportunities to develop increasingly erotic situations inside the narrative, usually only offering a "pimp" or "not pimp" box option which makes for a boring and flat story. Authors have to figure that if their main storytelling interface are words, then they have to make them interesting, else you're better off checking pornhub or something.
Again, the old j-ero games pitfalls of lackluster build ups, dead horses, abrupt sexual development, dependance on rape and prostitution makes this game another run-of-the-mill experience.
That said, if this game would undergo some 2.0 treatment - preferably with a writer, or after the author learns more about writing - this game already has the framework - and potential - to become something incredible!