They're inseperable though given that "dominating" is the method through which she lies.
False. Their strongest chemistry moments are precisely when she dominates him by telling him the truth; those are precisely the moments where they truly connect, like in chapters 24-25, or even 26, or this very chapter 26.5.
She doesn't need to lie to dominate Yuu; that's what he tells her repeatedly, even in chapter 28—again, Maruto emphasizes that Yami is honest in believing everything was resolved at home. She doesn't need to lie to play the flirtatious senpai/shy kouhai game with him.
He's making her cosplays and she's explaining the context for those costumes
Yes, that's the point. She doesn't need to explain that context or go into so much detail, nor did Gojo ask her to. "Just make me this cosplay, that's all". Gojo is mainly interested in the clothes, not in the character´s story. Marin talks about these things and speaks so openly about them because she is hypersexual and obsessed with eroge games; in fact, it's something that caused her problems in the past. Gojo accepts Marin as she is, just as Yuu does with Yami.
You told me your Aya/Yuu first time fic on me despite me not being a fan of the ship—does that make you hypersexual?
We are literally in a thread discussing this series. It's very obvious you are following Imasara in first place.
As a woman, no, not at all. There's no universe where a 'normal' teenager living in a culture that opposes promiscuity would want people to think she's promiscuous. That's the most insecure thing a girl can be.
Yes, that's the point. Marin is anything but normal; there's a reason her father took almost 100 manga chapters to appear and is almost never home because of work, and her mother is dead. A "normal" girl doesn't dress so revealingly at a public convention, implying she's promiscuous. Gyaru culture is precisely about girls who want to be seen as promiscuous (being really or not), and Marin certainly plays into this reputation, even if she isn't. There's a reason she identifies with Shizuku Kuroe, a character who had sex with 17 men in her eroge.
That's why, in manga, girls who openly brag about their sex lives are often portrayed negatively. I'm denouncing bragging because sharing stories to ask for advice is a different story
Aya isn't bragging or showing off. As I said, she tells these stories in a way that may or may not have happened; she changes many details to make them less plausible (hence her turning Yuu into several men), and above all, she doesn't say it in public, but rather at a sleepover with girls she supposedly trusts—as Ayami repeatedly told us about Hikari. She does so, in any case, as if it were "my glorious past that will never return," like someone who wants to present herself as a repentant sinner.
The only girls I knew in high school who went into such graphic detail as Hikari says Aya does were in very complicated relationships that didn't last
You're not Japanese, and you're applying Western rules to a culture very different from our own.
No, because this is a different manga. Jane Austen's stories usually have a similar structure and character profiles, but the intelligent and sensible Elizabeth is a fundamentally different character from the intelligent and sensible Elinor
Takamura remains being an Expy of Izumi, and everything we've seen of him —not least his chapter with Haru, a complete stranger who nevertheless spends the entire chapter scolding him and extracting information from him, as if she were his mother—is definitely proof that he's just like Izumi in this respect and that his parents surely forced him to talk to them about Yami at some point in their relationship and give them what you called the "PG version"
The only thing he managed to hide from Haru, mostly out of fear of legal repercussions, is sex.
And Haru is by no means the first time we've seen this in Yuu. Chapter 3 of the omake, where his parents interrogate him about why he wants to take the entrance exam for Hikari's school, is another example of how interested they are in his life and how they will pressure him to talk—and Yuu did talk on that occasion. Someone like Yuu Takamura is incapable of withstanding real pressure, especially when he knows he's lying, and this is a trait in which he is identical to Yuu Izumi.
If someone like Yuzuka was able to notice it so quickly with Aya, when she doesn't even really know her well—as I said, if Yuzuka truly understood Ayami, she wouldn't call her by her hated abussive stepfather's last name in first place; this is something Yuu did understand quickly in chapter 22— Yuu's parents should have noticed it much faster with their son, especially without being able to use Hikari as a cover.
There are ways to prove that Elizabeth and Elinor are different characters and not Expies. With Yuu Takamura and Yuu Izumi, it's not so much the same anymore, because, as I said, Takamura is directly an Expy of Izumi. Even so, on this specific issue, there's no indication that Takamura is better at hiding things from his parents than Izumi was. All the evidence points to him talking very easily under pressure, and he probably spoke as soon as his parents started pressuring him.
The chapter ends with Hikari apologizing for being annoying. You mention Haru as 'if only Hikari had pressured him,' but Haru and Yuki don't have to pressure him. Haru asks if Yuu will talk, and he vents. If anything, Hikari pressures him even more by asking Yuu and then pointing out that he's avoiding the issue.
Haru definitely pressures Yuu several times during the conversation, especially when Yuu utters the (in)famous "Yami-senpai didn't nothing wrong." At that point, Haru reprimands him mercilessly, completely unconcerned that Yuu whimpers and begs for forgiveness, and she never apologizes for treating him the way she did.
If Hikari is incapable of enduring Yuu whimpering or crying for more than 5 seconds, even though Yami could, and this is why she avoids Yuu —because she's a coward unable to withstand his puppy-dog gaze and voice— then she deserves where she is now if she lacks even that minimal own willpower.
Yuu isn't avoiding the conversation with Hikari. He denies once that Seki is his ex-gf and clearly states that he feels uncomfortable and doesn't want to continue the conversation. Instead of asking other questions—as Haru does— Hikari persists with the same question, believing that Yuu is lying to her. That "you're trying to change the issue again" is nothing compared to Haru's dismissive "if you say that, you'll only make things worse" comment to Yuu in chapter 43. In fact, Yuki is actually much kinder to him in comparison.
Hikari simply never pressured Yuu. Real pressure involves risking whining and crying. She also never asked the right questions, plain and simple. She never asks, "Did you have an ex-girlfriend?" And most importantly, what bothers Hikari isn't that Yuu has an ex-girlfriend, nor that he's uncomfortable talking with Hikari about her. What bothers Hikari is that "Aya-chan" turned out to be that ex-girlfriend. That's what broke the unspoken agreement between Hikari and Yuu on the matter.
"I guess I misremembered the boyfriend thing, but Haru enthusiastically encourages Hikari in the early chapters. In chapter 43, she's dismayed by the situation, but what makes you think she dislikes sex?"
Not, Yuki was who did it. Haru encouraged Hikari to kiss Yuu, very different. She supports Hikari when Ayami and Yuki talks about Hikari has to directly have sex with Yuu.
And that's why she tells everything to a complete stranger?
If by "complete stranger" you mean Yami, we return to the point already made. Yuuu falls in love with Yami at first sight; he feels that she's protecting him. That doesn't mean he's stopped loving Hikari. But he loves both girls at the same time, even though he chose Hikari over Yami in chapter 40. That's why Seki calls him that, and that's why Yami herself says she feels the same way in chapter 39.
Also, the scene where Yami pressures Yuu if he is in love with "that girl of our school" in chapter 23 is other scene practically copied word by word from Shikimori-san, where there is an almost identical scene with Kamiya directly asking Izumi if he got a girlfriend and who is the girl and how they became a couple (anime episode 7).
And she tells Hikari about Seki? There's a huge difference between keeping your private life private and hiding a girlfriend because you think she'd ruin your chances with the girl of your dreams. The latter is terribly unfair to the girlfriend, and I think it's unbecoming of a 'decent and honest' Yuu
Well, that's what we had with the exam. He never told Hikari anything about it, but he did tell a classmate he won´t seen in years after the failure. His parents never told Hikari either. This is much worse than him hiding a relationship with an ex-girlfriend that ended catastrophically and traumatically for him, and which included things that could land Yuu in jail.
Yuu tells Hikari about Seki because he's opening up now to her. Hikari manages to repair their friendship, and Yuu feels that she's finally showing more interest in his life (omake 5).
Yuu "hides" Yami not because he thinks she'll "ruin my chances with the girl of my dreams." At this point, he's already decided to give up on Hikari. He "hides" Yami because his cowardice prevents him from completely closing the door on Hikari, which is very different.
"What Aya wanted was that once tied down, Yuu would fall in love with her"
I mean, this was exactly what happened, with love public confession included. The only doubt is about the FIDELITY of Yuu.
"Or Aya thinks she's the side-piece, which is kind of true if Yuu's hiding he "Hikari's way of protecting his chances with Hikari"
What chances? Yuu himself told Yami in chapter 24 that he thinks Hikari will never reciprocate his feelings. This is his own pain, which he'll believe the next morning when Yami comforted him, and Haru confirms this in chapter 43. This fits better with Ayami knowing she's the "plan B," "you're with me because Hikari friendzoned you." And even though she knows Yuu is loyal to her, she's still bothered by being haunted by Hikari's ghost.
that's why her friend predicted the ghosting long before the attempted suicide
The girl never met Yuu or the efforts he made to maintain the relationship. She only knew Yami's side and has no way of knowing who Yuu is or what his motivations are for dating Yami. The suicide attempt was indeed a strong reason, and real, and that's why considering it a mere "excuse" is fool. Yami genuinely feels guilty about what happened.
Yuu looks for her until he sees Hikari and then he stops. At that moment, hiding Aya's existence from Hikari is more important than finding Aya
You're going with your headcanons without any textual basis. Nothing suggests the point Yuu renounced still looking for Yami is when he saw Hikari and hid from her. He continued searching after that, and nothing in the text suggests that was the last time. Nor would Yami have any way of knowing that Yuu hid from Hikari at this point, unless she is actively hiding from Yuu at this point and knows he's looking for her and decides to avoid him.
"Where are you reading disgust in Haru's thoughts?" Yuu describes the relationship as starting from a place of hurt/comfort.
Yuu's words are a very different and more favorable description than "two dogs licking each other's wounds". Haru is dismissive here, and her mental image of Aya naked as an ugly, cold, and anorexic woman emphasizes this, when the actual image of Aya during that first time with Yuu, which we see in omake 4, is very different and much more vibrant.
Here, Haru represents the pro-Hikari audience that thinks Yami is practically a slut who slept with the first person who came along during her bad moment. Haru is disgusted by the idea of Yuu being the boy from Yami's stories and that those stories were actually real. Haru doesn't buy the tragic romance narrative that Yuu offered her.
There's nothing in his POV about Aya protecting him
This is in omake 3, right when he meets her:
The cold wind blowing in front of the station pierces my ears, which I can't hide behind my knees. Compared to my right ear, which is about to lose feeling, my left ear doesn't feel as cold. It's as if there's something next to me on my left that's protecting me from the cold wind...
I felt a little warmth and sensation in my left ear. A cold, slightly sharp voice...but also a very pleasant one, flowed in.
"It's annoying when you're just whining in a place like that"
So...
It was creating problems earlier though, like the exchange. In chapter 28, where Yuu flags that she's always lying,
Well, here he's complaining because she hid her family problems from him, and he rightly thinks she's underestimating her issues at home. Once again, it's external pressure that's really causing problems between them.
And anyway, as I already said, their dynamic is good as long as they're honest with each other. The problem is that Yami lies instead of trusting and opening up more to Yuu. If only she had been more honest with Yuu, as he asked her to be in that same scene, the relationship wouldn't have collapsed.
Aya is hurt that Yuu doesn't believe her about moving in together
Still not enough to justify such a radical change between chapters 28 and 29. It's obvious that Yami got a call during the mini time-skip between those two chapters.
"Up until she trusts him enough to tell him she wants to move in together and he completely doesn't get it."
I didn't say that dynamic was perfect or that he always could see through her mask, Hikari couldn't either —otherwise, she would have noticed the change Yami underwent in the last few months, which Yuki mentions in chapters 42 and 43. And again, it's still a scene where Yami could have made it clear she was serious, and Yuu would have responded seriously.
That's the point. If Yami hadn't actively lied, she surely would have saved her relationship with Yuu.