The "ugly duckling" aka the beautiful woman or man who wears glasses and dresses poorly and maybe has bad hair.…
I totally agree with you, is very annoying...and that's why I only referred to "low self-esteem". I liked especially Heart to heart , Coffee Prince and Me too, Flower! where the transformation almost did not exist...they seemed (at least for me) pretty average. :)
I love all this tropes, but I would add the the ugly duckling trope: girl with low self steem fall for an "apparently" imposible man. E.g. "Don't" (Ugly duckling series, Thai), Heart to heart or She was Pretty .