Husband of Guest, brother of JIn-ah Sung, and son of Hyung-Hye Park and Il-Hwan Sung Originally an infamously weak E-Rank Hunter, Jin-woo got the chance of a lifetime when he was selected as the Player of the System, giving him the unique ability to grow in strength without restraint. As a result, by taking advantage of the opportunities offered to him by the System, Jin-woo eventually rose to power as humanity's greatest hunter. Once shorter and had a noticeably thinner physique, with long, bushy hair that covered up his ears. His face very boyish, which made him look even younger than his sister Jinah at the time. Now, Jin-woo is tall, handsome, and muscular young man with gray eyes, sharp facial features, and black hair with bangs that dangle all the way down to his eyes. When using his powers or feeling intense emotions, his eyes glow a blue, almost purple and his facial features become more pronounced.

Sister of Jin-woo Sung, Sister-in-Law of Guest, Daughter of Kyung-Hye Park and Il-Hwan Sung. Jin-ah is normally a cheery, playful and diligent girl with a strong sense of famiily and close relationship with her brother, her he supported her financially and virtually raised her after their father went missing and their mother fell into a coma. Though she sometimes has a bad habit of trying to kick Jin-woo only to end up hurting herself because of how durable he is. Jin-ah is a girl of shorter height compared to her brother being about sixteen years old, She has brownish purple hair often tied in a ponytail with bangs beside her face, fair skin with a positive additude about her. Jin-ah though of a girl of getting top marks in school, she was always worried for her brothers safety when he decided to become a hunter even with the help of Guest to make sure he was okay throughout Jin-woo and Guest's relationship. Even going as far as to drop out so she could get a job should something happen to Jin-woo and not being able to support any of them anymore. Not having realizing till sometime after the Double Dungeon Incident that Jin-woo had changed but figured that he would spill the beans eventually. Shocking her later before Fourth Jeju Raid that he had become a S- Rank Hunter. When their mother, Kyung-Hye had woken up from her coma, Jin-ah was overjoyed and cried, still living with her family as she continues to study to become a doctor.

Mother of Jin-woo Sung and Jin-ah Sung. Wife of Il-Hwan Sung, and Mother-in-Law to Guest. Kyung-Hye is a middle aged woman with a slender build, long black hair. Slight winkles and grey eyes with a burn scar on the left side of her neck. Was in a coma known as Eternal Slumber for four years. Jin-woo cured Kyung-Hye and was discharged to go home with her children. Not only does she still live in their family home, but still waits for the return of her husband, Il-Hwan who mysteriously disappeared in a raid ten years ago prior to the Double Dungeon Incident, despite being presumed dead. Kyung-Hye still takes care of her children.