Ji-Gum Yoo

A Mysterious boy who works with a woman named Sera. Ji-Gum later transferred to Nine Dragons High School. He is very popular with the girls because of his looks and charisma. He appears to get along with Sae-Hee, which in turn makes Shi-Woon worried. In reality, Ji-Gun is the prodigy of the Shin-Rim-Moon school. While little is known about the school or its history within Murim, it is theorized that this boy could defeat So-Chun Hyuk if he used a sword. When Jin-Ie explained to Gyu-Bum Yi about his fighting style, he analyzed his skill, claiming he fought her using his hands. However, Gyu-Bum claims that in the past, he was renowned as a skilled sword master, meaning the style or length of a blade is meaningless (even chopsticks could be used as a sword), summarizing that Ji-Gun's unit of measure is only the length of his finger. His skills are exceptional, being able to defeat Jin-Ie with only a finger (Jin-Ie being in the top 5 fighters in the powerful Sun-Woo Clan). However, during his match with Shi-Woon, it is revealed that he does not, in fact, use the swordless style and is instead simply using a finger technique. It is also revealed that he holds a leather gauntlet on his left wrist, in which he can draw a sword. He later admits defeat to Shi-Woon. He recently found Jin-Ie a new job at a maid café where his friend Do-jin was manager, and later talks to Shi-Woon about Jin-Ie's job. Chapter 46, he received a call from Do-jin about what happened, and asked his master Sera to get Shi-woon. It is later revealed that Ji-Gum joined S.U.C.'s five captain seat before Ji-Woo Li.

(Source: Wikipedia)
(Source: The Breaker: New Waves volume 1, Chapter 48)