A 6th grader who dreams of becoming a swimmer. The swimmer in Lane 5. She has short hair and a cute appearance. Although she is good at putting up walls, she officially starts dating Taeyang. Female. She is both a rival and a close friend to Cho-hee. She left the famous quote: "You play a match to win. I want to win." 13 years old. Main event: Freestyle.

Naru's close friend. Female. She wears her long black hair in a single ponytail. She is energetic and in the same swimming club. She becomes very close with Cho-hee. She often says the phrase "Sarang's Start." 13 years old. She hangs out with Dong-hee, Se-chan, Naru, Seung-nam, Cho-hee, and Taeyang. Main event: Freestyle.

Naru's childhood friend and Cho-hee's boyfriend. He has short black hair. Male. He is both a rival and a friend to Taeyang. The epitome of a tsundere. 13 years old. He hangs out with Sarang, Se-chan, Dong-hee, Naru, Taeyang, and Cho-hee. Handsome. Main event: Freestyle.

Naru's older cousin and role model. She has long straight black hair. She was originally in the swimming club but switched to the diving club. She left the famous quote: "Naru, you're different from me. You jump beautifully there. Even if the direction is downward, if you jump yourself, that's flying." Female. Main event: Diving. Cheerful and lively. 14 years old.

Short black hair. Playful and sly. He hangs out with Dong-hee. Main event: Backstroke. Handsome. Male. He's a good kid despite his mischief. It's assumed he spends weekends playing games or at the pool with Dong-hee. He often teases Sarang. 13 years old.

Wears her black hair in a bun. She used to wear a swimsuit she called a charm, but after a realization from Naru, she started wearing a different one. Female. She left the famous quote: "I learned there's something stronger than a charm." (Naru: What is it?) "Me." 13 years old. Presumed to be pretty. Dating Seung-nam. Main event: Freestyle.

Short curly black hair (presumed). Male. Main event: Backstroke, Freestyle. Quiet and reserved. Occasionally drops hard truths. He has chubby feet from training, but is presumed to be thin in reality. Might have a crush on Sarang. 13 years old.

Male. Presumed to have a crush on Beodeul. Main event: Individual Medley. Thinks Naru is cute. 14 years old.

Curly black hair and round glasses. He dates Naru, and Jimin constantly tries to flirt with him. Male. The tallest of the group. Handsome. Rival to Seung-nam. He is good at studying and has won various medals and trophies. He left the famous quote: "I'm always on your side. Even when you're not on your own side. Got it? Hang in there!"

Long straight hair and seems to have quite a few friends. Her appearance isn't particularly striking. Female. She likes Taeyang and tries to flirt with him every day... well, her target probably changes frequently. Not necessarily boy-crazy. 13 years old. Seems to be short.