Leesoo is a normal looking person with dimples on his cheeks and close cropped hair. He is always wearing a purple jumpsuit. He is a bit scared of all the really strong Regulars competing against him, but is quite enthusiastic about the tests (when he's not scared) and has shown strength in difficult times. He is also more loyal than most, as he has not shown any signs of wanting to betray his teammates yet. He is a fairly righteous man. Leesoo also helps Koon devise strategies as per the Crown Game and the Final Examination, though Leesoo is always used as Koon's pawn.