I'm probabaly part of a minority here, but I feel more sympathy towarda Nanase here more than Yuni. Throughout this story, I sense very little communication between both parties. When Yuni gets upset that her girlfriend is unavailable, rather than confront and tell her about it, she post her frustrarions of social media and ended up luring what essentially is a stalker. Seriously, talk to the girlfriend/boyfriend/lover. Do not expect them to pick up visual ques that you are upset and expect them to figure it out or else they might pull a HUMAN thing and believe that things will work out gradually and they need to deal with other issues at hand. Give an ultimatum if necessary. Say "Hey, I'm upset that the club is taking priority over me and that your catering other peoples affection over me. If you truly care about me, we should work for a way where we can spend more time together without any intrusion. If not, they we should stop being together". No one should ever be in a position where they are expected to be mind reader. That's the kind of thing that make relationships 100× harder than it already is. Always, always, always Talk. You don't need to expose any deep dark secrets or anything, just express your true feelings and show that you want to make things work. Even if that person is constantly smothered by everyone else and you can't find an impromptu time to speak your mind, use alternative communication methods like calls and text, or better yet, make that opportunity by putting your foot down and pull them out of that crowd. Seriously all this heart ache could be resolved in less than 5 chapters if the depressed upset girl who constantly complains about her gf not spending time with her had just properly communicated to her gf instead of having an affair with her stalker.
Thank you man, your comment was a breath of fresh air.
It surprises me how much people are defending this toxic behavior by using these circu that could so easily be solved with actual f*cking communication. All your suggestions of what she could've done are great and even if they didn't work, the right thing to do would've been to break up before going and fucking someone else, betrayal is never the answer and I hate myself almost as much as that girl because I made the mistake of starting this manga and now I want to keep reading it even because I wish her poor gf could get a happy ending, getting away from that scum, but sadly I doubt that will happen since it's obvious who the main characters are