Sung-Sun is very composed, mature, and intelligent, often advising her fellow Fracción, Emilou Apacci and Franceska Mila Rose, to stop arguing, for it makes them look weak, before chiding their angry responses. Her haughty aloofness often adds fuel to the fire. She has a habit of covering her mouth with one of her long sleeves, and has an incomprehensible look in her eyes when doing so. She has a sort of snobbish attitude.