Are we reading the same comic? Yuna literally tried to bait Min into a relationship just to fend off annoying suitors. She only admitted that it was a scheme after being turned down and cornered, and realizing she was a girl. Then Min told her honestly that she was willing to do an explicitly pretend relationship, and explicitly laid out that she was -not- looking to make it sincere, but Yuna has kept pressing continually. Yuna was clearly the one that was "using" Min at the start, and now that she's caught feelings, she's trying to impose herself on Min in stark defiance of their agreement.
Yuna is the one that started this for selfish reasons, and she's the one trying to change the arrangement for, again, entirely selfish reasons. I wouldn't go so far as to say Min deserves better, (she deserves better than that scumbag professor, tho) but Yuna could definitely do way worse.
Yuna deserves better because she was honest and let min suh know why she wanted this relationship while min kept her in the dark KNOWING she could possibly fall for her. Min couldve told her, her circumstances because yuna didnt plan anything serious at first anyways and it shouldve been on equal grounds but now min is just using her and dragging her with no choice into a mess that has nothing to do with yuna tbh min is pretty but thats all she got going for her