18 years old, 181cm male. A 2nd-year student at Baegwang High School. He is the vocalist and frontman of the band 'Watermelon Sugar'. He lives at Snail Boarding House, which is run by his grandmother. Though he seems simple-minded, he is actually deep-hearted and willing to risk his life for the grandmother who raised him. He is a person who loves with the most passion. He originally formed the band for Se-gyeong, who he fell for at first sight, but now he is more passionate about the band than anyone else. He has a handsome, fox-like face.

18 years old, 181cm male. A 2nd-year student at Seowon Arts High School. The guitarist for 'Watermelon Sugar'. He has lived his whole life as a kind and mature son. He has a surprisingly witty personality and has shown musical talent since childhood. Once he gets close to someone, he shows a bright side. He is an excellent student and even tutors Yi-chan. Because he came from the future, he is currently living at Snail Boarding House. He is highly skilled in sign language. He is a handsome boy with a puppy-like face.

18 years old, 167cm female. A 2nd-year student at Seowon Arts High School. The designer for 'Watermelon Sugar'. Born deaf. She is the daughter of a famous musical instrument company chairman and the board chair of Seowon Arts High School, living in a wealthy household. She suffers from bullying at school and home due to her hearing impairment, but she is overcoming it by gaining confidence from the members of Watermelon Sugar. She loves drawing and harbors a secret crush on Ha Yi-chan from the art room. She communicates through writing and sign language. She is cynical and shy, but once she opens up, she is cuter and brighter than anyone. Contrary to her appearance, she has a strong personality and says what needs to be said. As she was born deaf, she cannot speak. She is a rabbit-faced beauty.

18 years old, 168cm female. The cello goddess of Seowon Arts High School and the photographer for 'Watermelon Sugar'. Unlike the typical haughty student, she has a rebellious side and is very bubbly. She is popular for her innocent looks. She lives alone and is proficient in sign language. She is kind to Cheong-ah and they share a close bond. She is a cat-faced beauty.

18 years old, 175cm male. A 2nd-year student at Baegwang High School. The manager of 'Watermelon Sugar'. He is Yi-chan's best friend; he's funny but takes his work very seriously. He often shows traits of a producer, such as investigating incidents or finding solutions.

18 years old, 175cm male. A 2nd-year student at Baegwang High School. The genius bassist of 'Watermelon Sugar'. He is prickly about everything, but it's mostly just an act. He has a deep affection for the band.

18 years old, 180cm male. A 2nd-year student at Baegwang High School. The keyboardist for 'Watermelon Sugar'. He gets very nervous on stage. He has experience studying abroad.

18 years old, 188cm male. A 2nd-year student at Baegwang High School. The drummer for 'Watermelon Sugar'. He is a 'church oppa' type who attends church faithfully, but he absolutely loves rock music.