Nanase again created a terrible disbalance between characters.
She challenged Karma (laws of actions-reactions) again initiating everything, taking actions based on her narcistic selfishness. Again, she takes everything without giving a chance to other characters to express their needs and make choices good for them.
We saw how taking all without giving ended previously -with cheating and lots of following disasters which Nanase caused to happen by her selfish greed and negligence .
In my previous comment (chapter 18) I explained how those 3 characters are balancing themselves (some unconsciously and in darkness, some not). But now, when everything is in the open to all of them, Nanase makes a wrong move.
And it's not wanting to take back treacherous GF, it's wanting to keep the club and have the GF but asking from Yuni and Fuuko to cut it all between them.
She is basically forcing them to accept her conditions, giving Yuni illusion of choice and only promises that she will be good GF from now on. And she is leaving Fuuko in terrible emotional distress, and after all, she is calling her crazy?????? To act like she does and call the "defeated" character crazy? And if Fuuko is "crazy" is it ethical of Nanase to call her on it the way she does? Wouldn't it be dangerous? Hm...
And, what Nanase sacrificed? NOTHING!
She did not grow as the character, she did not change, she is still same selfish spoiled brat, just giving promises that she changed herself, but by her actions I don't see any change in her.
Even Fuuko's offer to be "a side chick to Yuni" was better balanced and more healthier situation than this one.
Outcome will not be good FOR NANASE again.
I must admit, I expected after reading 19th chapter, that Nanase will say that she will stop with club activities and ask from Yuni to leave Fuuko and be with her. That offer would be fair and it excludes Fuuko from the "game".
I expected that Nanase at least will sacrifice something for the GF she loves, even if Fuuko was left with nothing. But this level of selfishness and greed I did not expect, and such a violent action (emotionally violent).
And, finally, about Yuni's "choice". I think Yuni is clearly showing here her submissive side. That she just chose what turned her on in this situation. But I'm not sure for how long until returning back to Fuuko?
And about Fuuko, she must take her "punishment" for interfering between two girlfriends.
But she did not want to ruin them, just to balance them, so I expect she will come back with Yuni again.
Yuni still does not know clearly what she feels about Fuuko. But they are better match than Yuni-Nanase. Yuni-Nanase is already confirmed disaster of relationship. Can it change without Fuuko in equation?
edit: changed choose into chose (I did not know edit will return post into pending approval, sorry)