Soo Lee

Soo Lee is the main male protagonist of the series. He is a swimmer at Choa’s high school and inquires to help her learn to swim after she revealed herself as a mermaid who couldn’t swim.

Appearance
Soo has short brown hair and light brown eyes. His bangs are mostly swept to the right of his face. He is fairly tall and muscular.

Soo is usually seen wearing his school uniform, which consists of long black pants, a white collared shirt with a beige sweater on top, and a yellow tie. During swimming lessons, he wears black trunks and goggles.

Personality
Soo is very outgoing and, according to Choa, the loudest kid in the class. He is very friendly and persistent. Soo is also very patient, hard-working, and caring. He also seems to be very honest and open with his friends.

Soo doesn't hold himself up very high, however, as he believes he has no talent in anything except swimming, and doubts even that single talent of his sometimes. He's easily insecure about disappointing people and not doing well enough.

History
Soo has been close friends with Icelyn Lee and Chan Song since childhood.

Episode 1
Soo is about to leave the swimming pool after his meet, where he notices Choa gazing at the pool. Later that week at school, he inquires to Choa multiple times if she remembers his name or if she liked swimming. Soo then bumps into Choa at the pool, accidentally scaring her to fall into the water—causing her to turn into a mermaid. Soo then pulls Choa out of the water as he questions if she is a mermaid.

Episode 2
Choa confirms that she is, indeed, a mermaid.

Episode 5
Soo tries to convince Choa to learn swimming from him, and after a while, she finally gives in.

Choa Shin
Soo and Choa at first started off a bit awkwardly and worrisomely, but they did quickly began to get along and grow closer via their swimming sessions together. Then, over time, both of them seemed to have developed feelings for each other. They are still best friends and get along very well, though. Soo also helped Choa with learning how to swim via their swimming sessions, so that she could get closer to going back to the ocean. However, the closer Soo got to Choa, the more he did not desire for her to go back to the ocean.

Icelyn Lee
Icelyn is one of Soo's very close friends. It seems that Icelyn is a bit over-protective of him, though. She even kept an eye on Choa and confronted her about what she thought Choa was doing, which turned out to be incorrect.

Chan Song
Chan is Soo's other very close friend. Chan likes to tease Soo often, but the two of them still get along very well.

Woo Seon
Soo was suspicious of Woo at first, and even disliked him due to him continuing to call him "Swimmer Soo" - an intentional mockery of his name. So, Soo decided to keep an eye on Woo to protect Choa. Later on, however, they bonded together one day and became mutual friends after that. After Soo witnessed Woo assist Choa in various ways, however, he - who likes Choa at this point - seemed to begin becoming envious of him and seeing Woo as competition- so he didn't want to lose to him. Despite that, though, Soo still cared about Woo. For example, he checked up on Woo when he had a nosebleed, though Woo didn't approve. Soo was fine with that, and even remarked that he would react the same way.