Sun Hee is first introduced as a member of Ally's glee club. She notably does not speak any English, and speaks Korean throughout the episode. When Austin and Ally got into an altercation, she expressed that she would blindly follow Ally just to get a good grade, no matter how wrong she is. When given a choice between Austin and Ally, she asks, in Korean, to hear the pros and cons of both sides. Austin interprets this as Sun Hee choosing Ally, therefore, she is now on Ally's side. When Austin and Ally were both kicked off the glee club, she volunteers to be captain. When Dez took over the glee club, she expressed hatred for his leadership, wishing that he'd swallow his pitch pipe. She later sings a line in Korean during the mash up during regionals.
Sun Hee is revealed to have an on and off relationship with Chuck McCoy. Chuck called her a soul sucker while Sun Hee called him an obnoxious troll. Not long after, Sun Hee and Chuck get back together and she tells Trish to stay away from her man. She copies Chuck's signature "hee hee" throughout the episode. Later, she and Chuck entered the dance contest together. Although they didn't win, Chuck got the money and Sun Hee, in English, says "so long, Red" to Dez.
