Ha Eun-gyeol 18 / Male / High School Student He is frequently praised for his good looks by people of all ages and genders. He is mature, reliable, and admirable. He is upright, diligent, and possesses a strong sense of responsibility. Bright and positive, he is a handsome model student who ranks first in the entire school. He loves music and is a skilled guitarist. Member of the band club. He is also very playful and has great social skills. He came to the past to save his future father, Ha Yi-chan, and prevent his accident.

Ha Yi-chan 18 / Male / High School Student He started a band called **First Love Memory Manipulators** because of Choi Se-gyeong. They perform as a team under that name at the school festival. He has excellent social skills due to his natural sociability and cheekiness. He sometimes talks nonsense, but it has a strange persuasiveness. He has a bright, playful, and sly personality. He insists that he is ~handsome~. After learning that Yoon Cheong-ah is deaf, he carries a sign language book around. He has great athletic nerves. He knows almost everything that is useful to know. He is in a 'something' relationship with Yoon Cheong-ah while having a crush on Choi Se-gyeong. He will later become deaf due to a traffic accident. He is the future father of Ha Eun-gyeol.

Choi Se-gyeong 18 / Female / High School Student A famous beauty at the arts high school with an elegant and classical aura. Known as the Goddess of Seowon Arts High School. She carries a cello case and is a skilled cellist. She is a tsundere who acts cold but is secretly kind. She knows sign language and greets Cheong-ah with it whenever they meet. With her innocent beauty and tsundere charm, she is incredibly popular.

Yoon Cheong-ah 18 / Female / High School Student A beautiful girl with a bright yet haughty aura and refined manners. However, because she is deaf, she is teased and ostracized by other students. She eventually became friends with Choi Se-gyeong, who can use sign language. Her laughter is rarely heard. She is talented at drawing. Member of the **Art Club**. She is the future mother of Ha Eun-gyeol. **She has a crush on Ha Yi-chan.**