Love Chemistry That Worked Although They're a Polar Opposite

It's not good enough that they are simply represented as total polar opposites: e.g. 1) rich-poor, 2) dandy-tacky, 3) tsundere-gentle etc, but the story MUST give away proper development to their romance, and give enough nuances as to how they mutually fell in love with one another. and not through employing convenient plot devices (like cuteness/aegyo of the female lead or cohabitation). DO NOT INCLUDE DRAMA COUPLES WITH A LOT OF SENSED SIMILARITIES RIGHT AWAY (example of non-inclusions: the two people who connected with each other through fateful tragedies).