Glad Saki wasn't too late. :-)
I don't get the ending and even though it's an open one so whatever.
The only interrogation I have is why did she slap her ? She was already trying to kill herself, did she have to hit her ?
I think the slap came from her own frustration. She was frustrated that Konno was trying to take her own life, and even more so when it turned out to be true. as seen on page 18.
https://dynasty-scans.com/chapters/summer_lemon_and_overlay_ch08#18
I think Saki was, at some subconscious level, aware of Konno deliberately playing with her feelings all along, so that slap was a payback for the emotion pain she caused her. And, as @shrimpmayo said above, she may have also assumed that Konno was acting in extreme affect and slapped her across the face as a way to bring her back to reality.
Damn, human beings suck. If you wanna be self destructive and drag down someone else with you, at least have the decency to limit it to the people who hurt you in the first place. Don’t just pick a random stranger and dump a bunch of pain and trauma on them like that.
I agree that what Konno did was morally reprehensible, but I can also understand where she was coming from. Judging by her words, she has spent three decades obediently exorcising every last bit of her agency and self-efficacy from herself. She then had an early mid-life crisis and began breaking bad, trying to experience everything she had missed up on within three months. Konno effectively has the mindset and emotional maturity of a nine-year old child paired with means and power of a well-off adult in her prime. There is a reason why kids should learn social responsibility and boundaries while they are still kids, because if you grow up like Konno, without empathy for pain that your actions can cause, you will hurt people. And while I think Konno's manipulation of Saki was wrong, I think that her family is partially at fault for causing this entire situation in the first place.