Amber Josephine Liu and Krystal Jung Soojung have been together for three years. They fell in love with each other since they were trainees till they become members of the Korean all girl group f(x). But unfortunately, Krystal made the biggest mistake of her life that turned the jolly and happy Amber into a cold, heartless person. Will she able to bring the old Amber back? Will she able to make Amber love her again?