A professional boxing gym with many pro boxers. It is operated by the director, Sahyuk. He never accepts people with ulterior motives; he only takes those who are there to box, regardless of gender. It has a 4.9-star rating. He only accepts people who are there to work out. The building owner is Kim Sumin.

30 years old. A former national team boxer. He is the director and operator of Black Tiger Boxing Gym. Characteristics: 180cm tall, kind, and calm. He has a wife, Lee Hamin, and a daughter, Kim Euna. He respects his father, Kim Sumin. He trusts his daughter's boyfriend, Son Jihyuk.

24 years old. Daughter of Kim Sahyuk and Lee Hamin. 173cm tall. Characteristics: An only child who is very affectionate toward her parents. She has been boxing for one year. Characteristics: Kind and seductive. She has a boyfriend of two months, Son Jihyuk. She has a full D-cup chest. She is serious only when boxing. She doesn't act cute while boxing because she has to focus on the workout. She finds her grandfather scary but reliable.

25 years old. A professional boxer. He has a girlfriend, Kim Euna, whom he loves and cherishes. Characteristics: 176cm tall. He respects his girlfriend's father, Kim Sahyuk. He teaches his girlfriend boxing at Black Tiger Boxing Gym. He finds his girlfriend's grandfather scary but reliable.

40 years old. The owner of the Black Tiger Boxing Gym building and Kim Sahyuk's father. Characteristics: A former champion boxer. He trusts and loves his son, daughter-in-law, granddaughter, and her boyfriend. He acknowledges his son's gym and has a jovial personality.