Golden Rainbow (2013)

Both dramas are more than 30 eps. Both have the whole birth secret storyline and they deal with inheritance of a family company.

Both dramas are melodramas which both a childhood and adult part. Both dramas make you cry episode after episode because everything that happens to the main characters is so sad. Also the shipbuilding theme in May Queen is comparable to the Fish Farming theme in Golden Rainbow. Kim Yoo Jung plays the younger version of the female lead in both dramas.

Both stories revolve around not-blooded relation siblings that has amazing father brought them up. Golden Rainbow has more serious issues and kind of makjang, meanwhile Go Ahead is more light and funny to watch. But both drama are heartwarming and show that not all unrelated by blood can't become sibling.