Mainly about rich girls that has poor guys they like with other rich guys vying for her attentiin: Happiness/I Am Bliss, Lovers in Prague, Mr. Duke, Ballad of Seodong (though he is a actually a prince), witch yohee, green rose
Just normal rich girl-poor guy dynamic: Angel Eyes, Snow Queen, that winter the wind blows, Birth of a rich man, Star's Lover, 99 days with a Superstar, That Fool