So once in a while we get a dedicated actual NTR manga.
I said dedicated since this kind of works actually dedicate themselves to actually write a story. So the good news is that this manga has a story the bad news is that it is not a good one.

The story is about 2 assholes and a placeholder: The heroine Yuki, the NTRman Coach and the placeholder/protagonist Shouma.
The story revolves around these 3 and their ridiculous love triangle that is not really a triangle but it likes to pretend it is. Now before you inevitably bitch at me for not warning you about it: I don't know if the author is a woman or not but this manga has a lot of shojo lite/josei tones and sadly it's the bad ones, so I'm already warning you that this manga has a truckload of woman moments.

Shouma is a guy that isn't doing great at his sports club ironically because he's lazy and not focused however his life is great because he has been dating his childhood friend Yuki, whom became great friends one day when Shouma invited her to start running/jogging and saved her during a dark period of their childhood when she was feeling down.
Together they are a couple and no one seems to mind, take notes boyfriend in school = blackmail "writers". One day they get all hot and bothered they flirt inside the club's changing room and are discovered by the NTRman aka the Coach. Coach isn't very happy about this but something inside of him breaks, he kicks Shouma out and with Yuki alone he uses this chance to molest her this event would change their lives forever.

So the setting is beyond generic but if you know what you are doing you can work with it or at least the author tried to.
Yuki is the two goodies shoes genki sports girl that is cute and ditzy, her body is alright but the manga treats it as she's the goddess of beauty but I'm not gonna complain about that. Once she gets didled by the coach for some reason her switch turns on and becomes a turbo slut. And I think that's enough to describe what kind of decisions she proceeds to take in the rest of the manga.
The Coach starts just an strict teacher, he has a dark but not tragic past, however within that first chapter he becomes an NTRman and an assertive asshole. There's more to this transformation but at the end nothing justifies what he does and it's actually addressed in later chapters. He's very generic looking but all girls seem to love him.
Shouma is a placeholder, during the story he becomes every bad thing no one wishes and he's never happy. Constantly in fear, anxious, competing with the Coach, hard to describe because he's whatever the author needs to proceed the story. Innocent until he's broken, basically he gets the short end of the stick for the rest of the story. Very generic looking guy but ladies either hate or love him.

Art is just as you guess it very generic. Characters designs are grounded to reality for the most part so that's a good thing, you'll not see a massive ass or gigantic tits but most of the women have hourglass shaped bodies. Expressions are randomly good and on point, the art peaks mid manga but its downgraded for the final act, probably artist's fatigue. I say my favorite design is Koharu probably because is the most unique of all of them, also she's became a Stacy at the end for her man.

Sex scenes are definitively something you are not here for, they are short and sadly most of them are soulless. They are not hot and mostly there to be a vehicle to materialize the ideas that has been shared through the chapter, so most of them fail to do so. I think ironically the best scene is the one and only rape scene in the manga solely because for once you can actually feel what this scene means to the story. It's kind of sad because the scenes where characters make love are not passionate enough however the after sex scenes are pretty good if I say.

It is not the worst thing I've read, if you are into actual NTR works and I mean the ones with real stories then you should know we are currently swimming in a pool of trash low effort works era, but it sure is one of the most disappointing ones. With every step forward the author takes he takes 10 steps back: Lack of logic, nonsensical reasoning, common sense missing, cheap drama, worst shojo/josei tropes, main character abandonment, etc. I could go on.
Unless you eat this shit for breakfast I don't recommend you this if you are looking to scratch that itch for a good NTR story or a smutty soap opera.

Base +6