In !! era, Shu tries his best to embrace Mika's differences from him as an artist, since he's human and meant to grow and change, not a copy of Shu himself. However, I think Astraea's Atelier is the tipping point for where he actually makes that change wholeheartedly. Before the story, we know Shu's prudish, he especially gets mad at Mika for doing gravure photoshoots "meant to elicit arousal" (or however he describes it I forget the exact words. Hey Shu, what do you mean by this? Lol. My interpretation is that he's disgusted with himself for being aroused by it, but would never admit he was because it's "beneath him"). In Astraea's Atelier, Shu becomes more accepting of the fact there are different types of art, namely some that he might think are "unsightly" or depict things that he thinks are perverse/grotesque. But instead, he learns to look at them through a different lens, thus accepting that this type of art does exist, and being more open about it. I think he doesn't necessarily like the grotesque art Mika makes, but he does have an acceptance for it now that it's a valid form of art. And... he's a lot more willing to step outside his comfort zone.

So how does this play into their relationship dynamic... Maintenance. No one entirely knows what maintenance is, I believe it's kept vague and up to audience interpretation for a reason as it's *their* private time with each other, and related to the doll/master dynamic they have. My personal interpretation of maintenance is that it's a self care of sorts, like Shu cutting Mika's hair and getting him ready for live shows, as well as a physical process like stretching or massaging before/after practicing/performances. (Mika makes a comment or two that suggest there is definitely a physical component of maintenance, such as the "I want him to touch me, even if it's so hard it hurts" that make me think he's referring to stretching). I think maintenance is something intimate to them, even if it isn't sexual, it may be sensual at times.

"But wait, if Shu is prudish, why would maintenance have sensual elements?" Because the idea of maintenance is between doll/master, not between two humans doing sensual things. Shu is "taking care" of Mika as a doll, not as a human. With this disconnect, nothing they're doing is out of the order. Dolls need to be cleaned and dressed and taken well cared of. So if Mika's a doll, then he needs to be well treated too. By the time ! era rolls around, we know that Mika has to mostly beg Shu to give him maintenance. He has to ask for it, Shu won't just *do* it for him anymore. And I feel this marks the beginning of Shu really pushing for Mika to become human. Unfortunately, this leaves maintenance in a sore spot. Because giving your *unitmate* a massage and stretching him during warmups is sensual, isn't it? This one sided taking care of him comes across a little differently between two guys. Shu does offer to give Mika "special maintenance" in Sports Fes 3 so who knows what that means. But by now there's a level of closeness between them that most people wouldn't "get". Arashi mentions in Victoria that she doesn't entirely understand the dynamic between them, and it looks strange to outsiders.

Shu has no problem touching Mika, in fact Mika even teases him about it in Neveland later. Though Mika does ask permission from Shu, like to hold hands crossing the street and such, Shu usually complies. But whenever Mika spontaneously clings to Shu, Shu verbalizes frustration. To me, this reads as Shu not really accepting that he can be the object of affection. In exvalkyrie, he sang praise about Nazuna constantly, and we don't really ever see Nazuna saying anything back *to* him of the nature. In Shu's early stories, he is completely perplexed with Mika's devotion to him, he doesn't understand why Mika would stay with him after the fall, and kind of begrudginly accepts that Mika's just going to follow him around all the time. By !! era, I think he realizes that yes, Mika does care about and love him, but it's still not a conversation he's willing to have. He'd rather have things play out like a storybook, which is present in their stories like Antique Legend (Daddy Long Legs) and Acanthe (Sleeping Beauty). This is what imo leads to Shu making the assumption that Mika will move in with him after graduation, getting a little frustrated and saying Mika has been behaving "coquettish" with him. This line is important because it means Shu was definitely aware of all the times Mika flirted with him before, he just... didn't do anything about it in the moment, or if he did, it was a knee jerk reaction like he would in ! era.

Mika is hesitant towards Shu changing. We know this, like how he's anxious in Teddy Bear and Magical Halloween (! era stories) about Shu suddenly treating him a lot nicer. I think a more... sensual/sexual Shu would cause Mika distress and make him anxious about the state of the relationship. Even though he'd /want to have sex with Shu, there's some hindering elements. 1. His self worth, Mika doesn't see himself as desireable or even Shu's type. There's numerous mentions of him wishing he was smaller and cuter, especially like Nazuna (or even getting jealous of Kohaku in Antique Legend). He doesn't like his eyes, he thinks they make him look strange, even though Shu has mentioned he likes them. 2. Fear of change. As I suggested before, Mika gets uneasy whenever Shu changes. He has a view of Shu in his head that he thinks is the "correct" Shu, and whenever Shu deviates from that, he gets a bit anxious. 3. Humanity. Sex would be something very human for the two of them to do. It wouldn't be doll/master, it would be two people admitting that they feel a sexual attraction to each other. It's something that would leave them both vulnerable, and force some honesty out. Because I feel if either one of them were hesitant/cloudy about what they wanted, the whole thing would be called off. And I think Shu knows this, he can't just tell Mika "hey let's commence intercourse" (or achieve intimacy or however Shu would delicately phrase it) because then Mika would just comply. But Mika knows not to *ask* Shu because Shu's been shirking on 'maintenance' and for a while he'd been a bit bitchy about Mika clinging/touching him.

Let's dig a little deeper into Mika. I think his fascination with the grotesque is his own way of exploring humanity. Mika likes things that "no one else does", ie broken toys that he takes home and fixes is one example (that has also been implicitly compared to how he took care of Shu when Shu wasn't doing well). He's called a "broken doll" by Shu. Mika sees humanity as inherently flawed, and to an extent that humans are irredeemable. He's willing to dirty himself to keep Shu pure, as seen in Raison where he goes to grave rob to uncover the truth. But if Shu is human, doesn't mean that he's flawed too? Yes and no, I think at least for a while Mika views Shu in a sort of category of someone he has almost a divine devotion to. Shu is placed on a pedestal above him, but that doesn't mean he can't step down. If Mika can help it, he won't let Shu. I think this idea of not "dirtying" Shu would be one of Mika's biggest hurdles in a sexual relationship with Shu. Mika's a flawed human. If he has sexual desire for Shu, what's to say he's not tricking Shu into doing "perverse" things with him? Because Shu's prudish, isn't he... He would never want to have sex with something as broken as Mika...

I think in the current scheme of things, Shu's ready to have sex. Mika is not. Mika needs to increase his self confidence, and trust both himself and Shu more before he can accept that he's someone who Shu finds desireable, *and* someone who isn't going to "tarnish" Shu with his feelings / actions.