The important thing is that everyone around her KNOWS she's acting like trash and points it out including the main guy - unlike nearly every other romcom.
And she eats shit for it too. Not by some auto-losing rival that no matter how contrived things have to get for her to lose is going to lose anyways, but by her love interest, his friends, her friends, even her mother's badmouthed her.
That's massively different; it makes Hana a humanized, flawed character, instead of some inexplicably-beloved plot armored thing that should've lost.