Su-jeong is shocked to find out that the new hire she has to train is the ex-idol and her former bias, Woo-jin. At first, she's put off by how different Woo-jin seems from his idol days, but becomes more understanding when she hears about his stalker. When the stalker starts targeting Su-jeong, Woo-jin vows to protect her… only to find out that Su-jong's childhood friend Ki-tae has made the same vow…