I've yet to find a good Japanese NTR game.
That's a fair point. Visually, the average is magnitudes better, but that's a low bar and also really tertiary to writing and gameplay. An example I'd point to as great in all three respects is
Abaddon: Princess of the Decay.
While the writing takes a dip, especially with how it teases nearly good NTR only to rip it away and give you generic rape NTR instead,
Leane 2: Leane of Legitimate Crown is also good. The gameplay on a harder difficulty is fairly solid, there's a lot of variety, some fun tactics, if all somewhat half-baked. If there was a third entry, I imagine it'd be
really good because of ironing out the roughness.
It's tough... I think about so many I don't like, but then I realize they're still better than nearly all the western NTR I've come across.
Arms Devicer! has solid enough characters and really good set up, but then drops the ball hard with scenes that just summarize a bunch of events happening and basically skip it all. It does a lot to prepare good relationship dynamics with your motherly/older-sisterly friend that cares for and loves you and your much rougher friend who is licentious and playful, and certainly the type to tease the motherly one when she flirts with you. With gameplay that is average, writing that is unfinished, and characters that have a lot of promise, it's not recommendable at all, but it's still better than
Femdom Wife or
Sarah's Life or
Girlfriend's Amnesia or
Incest Story or... So on. It's a bit of a bitter feeling to me. I love NTR, but so overwhelmingly disappointed in the choices available. Gameplay is often bad. Characters are often terribly uncharismatic and retarded. Western's biggest problem is the abundance of grotesque, horrible, downright offensively bad 3DCG. Make them text-based instead, for the love of god.
There are good western NTR games--A Promise Best Left Unkept and Turning the Page, as well as (mostly) the Henteria games.
Since the first two are labeled "VN" I never checked them out, since 99% of the time, that's not a game. Sometimes they are, but since it's unlikely, I can't bother to sift through them all.
So, I can't attest to them.
Henteria is definitely weak on the gameplay front. there's little to none of it. The writing was servicable and fine, but the execution of the NTR with the lady of the house was poor. She wasn't interested in the antagonist, she didn't wantanything to do with him. It's been a long time since I played, so I could be misremembering, but I believe in her youth she had met him and was charmed. He was good with words, physically quite attractive, but then it turned out he was a scumbag and trying to take advantage of her, so she hated him. He returns, and there's just as much friction as ever, and he doesn't improve. His charisma and good looks don't soften her up and strain the relationship she's been building with the player, leading to tense moments where she's giving in to temptation to fool around with the strong and attractive guy despite emotionally being more invested in
you. Instead, he forces things on her, is sexually controlling, and basically rapes her into submission.
That's dull, that's generic, that's underwhelming, that's less impactful, that drags down her character, that's less hot, that's just faceless, lifeless, soulless NTR. And you got no good gameplay on your way there, and no good story or plotline framing it.
If the sister was your girlfriend, it'd have been a lot better, as her content would have made for at least decent NTR. She's naive, but genuinely interested in that guy, and giving him a chance that she really shouldn't, and he seduces her successfully. If you had a romantic relationship with her, there's a lot of potential there. No NTR with her, though. You aren't interested in her in that way. No dating options. She's just your sister.
Since I didn't like Henteria, I didn't look into the other chapters.
overly convoluted and unrealistic writing/gameplay in them
Unfortunately, neither east nor west has dodged