The Heirs (2013) - Season 1

Kim Tan is the heir to Empire Group who has been sent to study abroad in the U.S. In reality it's a form of exile, as his elder half-brother back home schemes to take over the family business. While in the States, Tan meets Cha Eun-sang, who arrived from Korea in search of her older sister. He feels himself falling for her, never realizing that she's the daughter of his family's housekeeper. When his fiancée Yu Rachel arrives to bring him back to Korea, his heart is torn between love and duty.