The son of Joo-wan's mother and her new husband. Described as a truly awful person who tormented Joo-wan relentlessly. He had a huge dog (almost as big as a person) that bit Joo-wan, leaving three or four scars on his legs. His gang also harassed Joo-wan's high school girlfriend, which led to her suicide. Joo-wan stabbed him in the leg in revenge, causing him to bleed profusely, but the half-brother smirked and made nasty jokes even while dying.
