Luka has unkempt blonde hair and yellow eyes of the same color. His fingers, from the midsection onwards, are a vibrant purple hue due to his heart condition.
He can frequently be spotted in a white blouse with an uneven hemline, which is cinched at the waist with a belt. Pearl chains cascade down from the top of his shoulder blades, while a sizable and lengthy bow is positioned at the back of his collar. He dons a pair of black, ankle-length slacks and plain white shoes.