People in this comic would do well to learn how to hold back on all the lecturing. You're not going to convince someone who's stubbornly reasoned their way into a corner out of it by telling them how they're wrong or making a mistake.
Just tell her that you'd appreciate it if she were to show up, and if she insists she stays at home, leave. So far, every time Kariu stubbornly sticks to a bad choice, someone else forced her out of that choice:
- When Kariu wanted to leave after Ohga, so he wouldn't notice her injury, Ohga decided to just grab her by the arm and physically force her on her feet.
- When Kariu didn't want to go to where Tamarai & Hishiron + Kaizaki were talking, Inukai grabbed her by the arm and just dragged her all the way there (across a staircase, in spite of Kariu's sprain).
- Now, when Kariu decided to stay at home instead of going to the match. Kaizaki learns of her address (what is privacy?) deceives her into opening the door, and forces his way in together with Hishiron.
Pushing back against her decisions is only going to solidify her stance. Let her make these mistakes and fail, so she can learn from it. In that case, if she were to try to change her mind she no longer has to consider the additional factor of "This would mean I was wrong and my patronizing classmates were right."
Didactically telling someone that they're wrong only makes it harder for them to consider that they're wrong.