Rin is thinking too much of others’ feelings, making their happiness hers
I think this specifically is gonna be a really important thing they need to address. Rin’s trauma around being poly is making her think it’s dangerous for her to want and so she’s distorting around it. It’s making her be weird with Mayuki, she’s putting up a strange emotional distance between them even when they’re getting intimate, and it’s preventing her from communicating.
Also, I went back and read the section where Rin leaves when Akira externalizes her insecurity at her, and it’s clear on re-read that Rin isn’t intentionally setting boundaries by disengaging after getting some gross stuff put on her, but rather running away because she’s afraid she’ll lose Akira’s interest or make her hate her. In other words, Akira and Rin are both afraid of loosing each other, which makes a really interesting dynamic, and you can see how they might come together.
At this point I’m not sure if Rin has a really minor crush on Akira that she’s suppressing which is causing her to lead Akira on, or if Akira is just jumping at normal things because this is her first crush, but I hope we’ll see.
Also people are talking a lot about how the kisses in this story are really intense despite not involving anything explicitly sexual, etc.—if I had time I’d go close-read the passages and make a comment from that, but I don’t, so suffice it to say it’s because 1) each scene is really strongly grounded in an emotional context both through the background we have about the characters and immediate setup right before it, 2) the artist really understands the physical acts of making out, how it feels, how it happens, and what it looks like, and can accurately depict this and 3) they have a really solid understanding of desire, and especially different versions of giving desire (Rin’s “I can’t help my self, I need to spoil you” attitude during thr adult kissing scene, Mayuki putting everything into doing her best to please Akira) which is itself naturally compelling and emotionally resonant.
All this is to say that Canno creates scenarios that are emotionally charged and grounded, and depicts them in a very expressive, verisimilitudinous way. I think this story is uncommonly good, and I usually hold off judgements until I’ve read to the end but this is shaping up to be one of the best yuri manga out there, period.