One issue with Nanase is that she seems to be too naive and really think the relationship can work, unless author is playing with us and Nanase is playing long game and faking it just to do a "fuck you" to Yuni at the end lol, unlikely but you never know.
I think biggest issue with Nanase is that she's scared of doing certain things with Yuni but then she goes and do those things with her friends like they're no big deal.
Her logic is understandable since as you said she's not just a teenager but gay too so she's scared of being out of the closet, I think what rubs some people the wrong way is that all the things she did with her friends are exactly some of the things Yuni wanted, she could have acted the same way with her and nobody would suspect they're gay, just close friends.
And then we get to the really shitty stuff like inviting Yuni to see her play but not help her get there and then she left Yuni alone, Nanase negligence can only be justified to a certain point, if it wasn't for the fact we know she's too much of a goody two-shoes we could have argued some of these incidents were downright intentionally malicious.
Yuri biggest issue is definitely that she's way too self centered, I do think it makes sense since the story makes pretty clear she's starved for attention and love, she's borderline broken goods, not that it excuses her choices of course, but it do explain them.
I think biggest thing they have in common is that they lack self awareness and aren't that bright:
In Nanase case she's too naive and don't realize just how bad some of her choices are, like how she keeps ignoring Yuni and focus in the club, yes Yuni is at fault too of course for not communicating, but it's clear she's not exactly thinking much about the relationship either.
In Yuni case she do realize what she's doing is bad, but not enough to understand just now bad it is and that she should either stop or break with Nanase, she literally can't see anything else besides who's gonna giver her the attention she's desperate for.
I think some people focus way too much on the cheating and demonizing Yuni, cause Nanase isn't exactly a innocent victim, but in the end the reality is that both are infuriating and frustrating for different reasons.
Really, people talk about how Yuni is bad because she cheated and whatnot, but when Nanase found about it she basically doubled down on the relationship lol, Nanase is fucking up just as much as Yuni at this point, only difference is that Yuni started worse due to cheating, I can't wait for Nanase to inevitably cheat with her friend lol
One could argue Fuuko is equally as frustrating and infuriating but unlike the other two she's completely aware of what she's doing, what she's doing is bad and she knows it, she willfully chose to do it anyway and she owns it, it's arguably worth of respect cause she's at least honest about who she is and what she's doing, really, admirable even.
