(Lee Min-ho) as Kim Tan The heir of the Empire Group. He is arrogant and self-centered however he is overshadowed by his older half-brother, Kim Won. He falls in love with Cha Eun-sang despite her poor background. (Park Shin-hye) as Cha Eun-sang Daughter of the Empire Group's housekeeper. She grew up with Yoon Chan-young and gets caught in a love triangle with two privileged men, Kim Tan and (Choi Young-do.) Kim Woo-bin as Choi Young-do The heir to a luxury resort. He has an IQ of 150, but uses his wit to put down and harass his friends rather than to excel in his studies. Kang Min-hyuk as Yoon Chan-young Son of the Empire Group's secretary. Cha Eun-sang's best friend who falls in love with Kim Tan's ex-girlfriend, Lee Bo-na. Krystal Jung as Lee Bo-na She lives a fabulous lifestyle as the daughter of an entertainment executive. Her first love and ex-boyfriend, Kim Tan never loved her. Yoon Chan-young heals her heartbreak. Kim Ji-won as Rachel Ryu Kim Tan's fiancée. A haughty and chic heiress of a major hotel group, she is a girl who wants for nothing in the world. Kang Ha-neul as Lee Hyo-shin Son of the Chief of Police. He is the student body president, and has a crush on his teacher, Jeon Hyun-joo. Park Hyung-sik as Jo Myung-soo Son of the CEO of a car import company. Quick to think on his feet, he's a slacker who doesn't want to inherit the family business. Choi Jin-hyuk as Kim Won Kim Tan's "perfect" older half-brother, an accomplished and capable young executive who runs his family's giant conglomerate, Empire Group. Im Joo-eun as Jeon Hyun-joo A teacher at Empire High School, she looks cool and collected on the outside, while being slightly awkward in real life. Hyun-joo gets Kim Won's attention for her sharp intelligence, although studying is the only thing she knows how to do. Kim Sung-ryung as Han Ki-ae Mother of Kim Tan. Yoon Son-ha as Esther Lee President of Chrystal Hotel. Mother of Rachel Ryu, and remarried to Choi Dong-wook. Choi Won-young as Yoon Jae-ho Empire Group secretary. Father of Yoon Chan-young, and previously involved with Esther Lee. Choi Jin-ho as Choi Dong-wook President of a luxury resort. Father of Choi Young-do, and remarried to Esther Lee.