"the prince" is actually NOT the girl's brother... the girl's "younger brother" was the illegitimate child... AND the mom was some bar hostess lady... blah blah... so the "prince" and the "younger brother" are half-brothers...

eventually, the "younger brother" moves into the mansion... and he abuses his power b/c he has a major sister complex... hooray... more attempted rape, but this time, it's from the "younger brother" not the "prince" *gasp. "younger brother" wants "big sister" all to himself... eventually the plan fails... whatever... the main girl forgives the "younger brother"... constantly saying that they'll forever be a "family" (i mean... seriously? he tries to rape you, and you still can call him your "younger brother"? sure he's not blood related to you... but you grew up together as "siblings" -- sorry... end of rant).

some other awful story arc... that's not memorable... for some reason, the girl moves to another island? and the "prince" follows her there... happily(?) ever after...