i honestly felt that their relation was really pure, it's true that the trope is weird if you see it from a third person's perspective but putting yourself in minji's position it wasn't really her fault, she lived her love with mi ju without knowing the fact that it was actually ga yeong's grandmother. I personally don't find it a bit weird, it was portrayed very beautifully and in the last moments of pan geum you must have noticed that for a few times minji called har as mi ju when she knew that it was pan geum. it really pains me how minji has suffered the weight of loss of both an elder and her love. please feel free to tell me and add to the discussion.