Kaoru may or may not have an eating disorder, but the thing Shizuka is referring to is their first breakup back in middle school, when Kaoru stopped eating until Shizuka promised to stay friends. Basically, she's asking Kaoru if she's going to start shit now that they're through. See here: https://dynasty-scans.com/chapters/virgins_empire_ch61#6

Ho, yeah you're totally right, I forgot that. Still, the analogy between Shizuka/haircut and Kaoru/eating problem remains and 'did change' vs 'did not change'. So what to conclude ? That Kaoru is still ill of love ? But because of Mayoi ? OR because of Shizuka ? Both ? Someone (sorry can't remember who) in the comments talked about polyamor and I think I agree. She says she will not going sentimentally but she just go for it one minute after.

Ok folks, I have a theory about that cryptic chapter. It's just an idea, I'm not sure. I didn't see this theory on the posts but if there were already, sorry.
So, there is Shizuka's haircut as an element, but also the eating problem of Kaoru. Indeed, she seems to not eat enough : Shizuka tells her "are you eating well" and Kaoru answers "I'm eating fine...neither of us are the same as we were then". So that means for Shizuka that she had long hair and for Kaoru she was kinda anorexic (that's first step of my theory).
It is confirmed that Shizuka did change : she cut her hair and, what goes with it, she's dating Mio (which is implicit in the text). But, Kaoru faints twice, and I think it's because she didn't eat enough.
So, maybe (final step) that means she didn't change that much in the (not as she said and not as much as Shizuka did change).
Does it make sense ?

Even tho, I'm in the team of "Kaoru making progress" (very slowly), but that's not part of the point here.

This is a freaking masterpiece in every aspect and deserve all the praise and recognition.

The peapole who religiously worked to bring us this work have all the right in this world to call themselves chads, no less.

Thank you .

Hell yeah.

Shizuka's not a power-bottom. She certainly wasn't with Kaoru because it's pretty evident that Kaoru prefers to corrupt good girls. That's why she cooled on Hibiki so quickly. See the cotton candy scene at the festival.
Look at Mio and Shizuka's early interactions. Even the moves Shizuka makes that look aggressive are invitations for Mio to take the lead. I think Shizuka was playing at the seductive senpai role to spite Kaoru, but she couldn't help revealing her true nature. She seizes the role she really wants at Valentine's, giving Mio chocolate and assigning her White Day responsibilities. Their first kiss is her inviting Mio to kiss her. She remains seated while Mio stands over her. Shizuka doesn't want control. She only steers Mio toward topping her. She's all bottom. (as mentioned, in a relationship power dynamic sense.) I don't think what Mio exhibits early on is Top energy as much as the single-minded possessiveness Shizuka couldn't get from Kaoru. Shizuka 100% wants to be someone's sole possession, but the most she would ever be to Kaoru is the centerpiece of her menagerie.
https://dynasty-scans.com/chapters/virgins_empire_ch126#6
and then Mio, without realizing it, auditions to be her possessor. Shizuka's eyes on the next page are her realizing that Mio is actually everything she wants. The same eyes as when Kaoru realized she was losing her grip on Shizuka. The same as Kaoru falling in love with Mask at a glance. They're significant shifts in the love triangle. The die is cast in Ch. 126, and what follows is the necessary shedding of a toxic relationship to make room for the new one. Kaoru is a fun character, and I think she could have an amazing redemption arc with Mask, but she still knowingly manipulates Shizuka. It's only this day in the story that Mio begins to understand she has to take the lead. She sees Shizuka's weakness and realizes it's up to her to pull her out from under Kaoru completely. She's always been stronger, braver, and more honest than Shizuka. She only lacked confidence while Shizuka's confidence was only ever a facade. Losing your virginity can be a big confidence boost, so I'm really curious about what happens next. Mio's not going full Yuu-sama anytime soon, but Shizuka's definitely down for the spanking.

Great analysis, I agree, i also always thought Mio is way stronger, I even think she's smarter. About Yuu though, as I said long time ago on Mangadesk, for me it's Mari the true top (more precisly the one who has the powerpower, see for example chapter 75 page 6 when Mari convice Yuu to stay at Mahi's) she just like to pretend to be bottom for Yuu who lacks a lot of self-confident - and they both enjoy their roles of course. Well, it's more subtile than that of course, always is.