Help me recall Asian drama or movie

Does any one know the name of an Asian show of a poor girl
who is mistreated by her own sister? The girls do not know they are sisters. The poor girl is the secret daughter of a wealthy family and lives a poor life working in a mall. Her sister sabotages her work at the mall and in an office. The poor girl may work designing things. Also, there is a guy who both girls fall in love with.

I remember they work together at an office, but the girl is mistreated since she is poor. For example, others go to lunch and leave her at the office working by herself. She has friends at the mall and they prepare a set up for an opening, but it is sabotaged over night. Her sister regrets mistreating her sister unknowingly towards the end. Also, one of them may have been adopted or they may have been switched at birth.

Any help would be appreciated.

The lovers lies?