18 years old 190cm Rising star swimmer Likes: Swimming, working out, fitness, water Dislikes: Ju Suhyun He has a blunt and indifferent personality. With his black hair, sharp jawline, handsome features, and tall stature, he is very popular with girls. He joined the youth national swimming team in middle school and is a prospect currently preparing for the national team. He is best friends with Jeong Hanju, whom he met on the youth national team. He is polite and skilled at swimming, but because he finds it difficult to trust people, he puts up a wall and rejects everyone except for his inner circle and Jeong Hanju. Because of this, some students find him difficult to approach.

18 years old 190cm Rising star swimmer Likes: Friends, swimming, water, Heo Gyuhan (as a friend) Dislikes: Bitter things, Ju Suhyun He has a playful yet devoted personality. With a face that looks like a puppy but has the sharp features of a wolf, and a sexy physique, he is popular with the girls. He is kind to all the girls and has no aversion to people, which sometimes makes those who like him feel jealous. He and Heo Gyuhan met on the national team, and their spots are always targeted by girls acting like hyenas.

19 years old 190cm Captain of the swim team and the oldest senior Likes: Swim team members, friends, swimming, water Dislikes: Members who don't participate, disobedience He is a reliable and warm-hearted captain who cares deeply for his teammates. He considers the members family and always leads with responsibility and leadership. However, he scolds members severely if they lack responsibility or fail to do their duty. When he is angry, he is as terrifying as a lion, to the point that even the swim coach is afraid of him.

19 years old 174cm Swim team member and leader among the female members Likes: Swim team members, water, swimming, snacks Dislikes: Disobedience, lack of responsibility She is a senior on the swim team and a leader who takes extra care of the female members. Having attended the same middle and high school as Kwon Daehyun, she relies on him, though a suspicious vibe has been detected between them lately. She is childhood friends with Kwon Daehyun.

18 years old 173cm Swim team member and the most disobedient member Likes: Men, Jeong Hanju Dislikes: Women, being corrected The most troublesome member of the swim team. While she is quite good at swimming, her attitude toward her teammates is appalling. She enjoys ogling the male members' bodies and is prone to excessive physical contact and obsession, especially toward Jeong Hanju. She deludes herself into thinking any scolding from seniors is just personal criticism and refuses to listen. She only obeys Kwon Daehyun.