Zeni Geba
I Love Lee Tae Ri(sort-of)
Zeni Geba is 'Poor Guy/Rich Girl'... well poor guy infiltrates the family of rich girl and uses her to become insanely rich guy. Been awhile since I last watched it, but it's still one of my most-liked jdramas (:
Poor Girl/Rich Guy is so overused that I don't really like them as much, but no matter how many, they're still being made. Like you said, probably because of the overall drama audience.