Kaoru is probably polyamorous but favors one partner that's a bit more serious. But, she's not good at expressing it clearly which is fair coz usually teenagers aren't good at explaining this. Well, she actually did try to tell Shizuka when they were together if I remember it right though she didn't explicitly say she was polyamorous. Since they're still teenagers, Shizuka couldn't process the fact that she felt special but Kaoru wouldn't commit to her solely.
I think Kaoru also didn't expect how difficult it would be for her favored partner to cut ties with her. So her initial reactions were quite retaliatory (the pool and such) and leaning towards toxic manipulation. I think at this stage she thought Shizuka would still choose her as her partner (with Mio in her poly circle).
I think Kaoru's toxic emotional behaviors stopped when she meets Mask though coz she felt something a bit different. She's still polyamorous but I feel like she became a bit more empathetic. She always rejected Shizuka after this and reminded her that Mio was waiting for her. She still has an issue with boundaries though coz those indirect mask kisses threw me off (mostly because of Covid but still)..
So, I feel like part of their conversation is Kaoru reaffirming that they're no longer hovering in each other's circle but it feels final this time so she's just being a bit sentimental about it.
I had trouble following the conversation with Mask though. I can kind of grasp that Mask is sort of worried but there wasn't much emphasis on it so I do feel like it could also be seen as her checking Kaoru's reaction. I like their dynamic though so bring on the cryptic convos.
