Ha-ill Gang

He is a prominent character and member of the Sun-Woo Clan, being a somewhat close friend of Jin-Ie Kwon. He is a top master of Sun-Woo and a skilled fighter, as he had been hailed to be quickly recognized in the Murim World. Despite his youthful appearance, he is at least in his mid to late twenties or early thirties as he was seen to be presumably around ten years of age before Jinie was even born. This mistaken impression may also have been helped with the style of fashion he employs.

(Source: The Breaker Wiki)