I’ve been thinking more vis a vis the consent issue, and why some people are bothered by their relationship while others are fine. To even know that Sarasa offered Mio a way out during the leash play you definitely had to read between the lines, as it wasn’t really explicitly stated. She was saying basically that she wouldn’t remove the leash and collar herself because what they were doing wasn’t just a casually on-and-off thing, like “wearing a pretty choker”—basically that this was something more than what they had been doing on the ride to school, and that Sarasa wouldn’t take the collar off Mio herself if she was feeling some big feelings because that was part of what they were doing; that Mio had to decide to stop it. If you didn’t catch that implication (and frankly I’m not 100% sure I’m not reading it into the story for my own comfort), her ignoring Mio’s fear is obviously super fucked up, but of course even beyond that what they’re doing would be a super unsafe way to do BDSM IRL—no discussion of limits, no explicit statement that Mio controls whether the scene stops, etc. so I totally understand people that say this is all fukt, especially if you were looking for a more realistic BDSM relationship.
With regards to people feeling uncomfortable about Sarasa saying she couldn’t control herself and thinking that means she’s just inflicting her desires on Mio, I think there’s more textual evidence to prove that’s not the case. She frequently checks in on Mio and is attentive to her in various ways; she makes sure the collar isn’t uncomfortable or hurting her, she assures Mio that what they’re doing isn’t shameful or bad (just a secret between them), and she helps Mio not drown in herself by helping her ground when they’re on the bus. I think her statement about being unable to control herself is more in the context of what type of love she wants vs. needs—in that scene she’s talking about how since she loves Mio, she can’t help but want to do more BDSM stuff with to express the way she cares and wants. Personally, I think that exploration of being true to your desires is really sweet. The whole chapter is, in a certain way, about how all this is her version of the fluffy yuri scene in her book, and I think it’s cool to see BDSM framed as a way for people to express their love.
So yeah I can definitely understand now why people are uncomfy or disappointed with this. I think that to tell the story Mira wanted to tell—about two girls who can’t directly communicate their feelings to each other doing it through the exchanges of BDSM—it would be tricky to work in a way for them to establish good boundaries and consent, but not impossible, and I think the fact that the work fails to do that means that it earns the reception it has gotten. Personally I’m really enjoying it, but I have a better appreciation now for how valid that different perspective is.