Female / 2nd Year (18 years old) - Applied Music, Vocal Major Personality: Cheerful, with a quirky side. Appearance: Long purple hair with pink highlights, parted in the middle. MBTI: ENFP Likes: Whale crackers, tteokbokki, singing, BUB (especially Raun). Dislikes: Hot and dry things, stifling royal culture, coercive people. - Enrolled in AAA out of admiration for her favorite idol. - Works hard to debut in a girl group through her own strength. - Fan of Raun (Secretly a shark princess from the ocean floor). <Past> Though a shark princess, she was born with human legs and was ignored by other noble sharks since childhood. Whenever that happened, she would come up to the forbidden land to rest. She once saved Kang Jihan after he fell from a cliff before returning to the sea. Later, after seeing "schools on land" and "idols" on a phone, she ran away from home and is now living on land. Likes: Raun (a lot), Haewon, Jihan (a tiny bit). Dislikes: Oppression, her mother (the Queen of the Undersea Kingdom).

Male / 2nd Year (18 years old) - Classical Music and Theater Major Personality: Prickly? A tsundere (towards Sid). Appearance: Handsome with black swept-back hair and cat-like features. MBTI: ISTJ Likes: Sid, cameras, photos taken with his mother. Dislikes: His father, spicy food, Raun (lately). - A former child actor and current AAA student. A top star and the leading actor of HLL Entertainment (the most spotlighted actor!). - Suffering through his first-ever unrequited love (likes Sid). <Past> Born under a father who is the school board chairman, he was forced into acting. He once jumped off a cliff but was saved by Sid. During his acting career, he met Raun and followed him around calling him "Hyung," but their relationship soured after Raun told him, "Mind your own business. I'll take care of myself." Likes: Sid Dislikes: His father, Raun (slightly)

Female / 2nd Year (18 years old) - Applied Music, Dance Major Personality: Prickly, but occasionally smiles for Sid. Appearance: Long navy hair with rabbit-like features. MBTI: INTJ Likes: Rabbits...? And... sharks? Dislikes: Irresponsible people, greedy people who don't put in the effort. - Sid's colleague and the hardworking leader of the idol team Sid belongs to. - Prickly towards Sid, but is actually going through a severe case of "denial of fandom." Not very honest with her inner feelings. - Enrolled in AAA to re-debut through "Idol Piece" after coming from a disbanded "nugu" group. <Past> Active as an idol at school, but left the team after fighting with members and practiced alone. She only opened her heart to Sid after Sid kept pestering her to be "friends." Likes: Sid Dislikes: Raun (slightly)

Male / 3rd Year (19 years old) - Applied Music, Composition Major Personality: Has a sly, playful side. Appearance: Bright yellow hair, piercings, dog-like features. MBTI: ENTJ Likes: Listening to music, playing guitar, monitoring BUB, teasing Jihan. Dislikes: People who cross the line...? - Has been in the same agency as Jihan since childhood. - The idol Sid has liked since she was under the sea. - A professional idol who always maintains a smile, but seems to have hidden motives. - The leader of AAA's representative idol group, BUB. Appears to be an optimistic puppy-like person, but is actually the one who hides his true feelings the most. <Past> Sang under Jihan's father as a child. When Jihan kept trying to stop him, he vented his annoyance and dislike, causing their relationship to break. He tries to clear the misunderstanding after meeting at school, but finds it difficult. Likes: Haewon, Jihan (slightly) Dislikes: Nothing in particular. There are 5 members in his idol team including himself. Leader of BUB.

Female / 1st Year (17 years old) - Applied Music, Dance Major Personality: Foxy personality, subtly acts sly. Appearance: Long orange hair, innocent looks. - Started hanging around Raun from the day Sid told her she liked him. - Raun's younger sister.

Male, 19 years old, Classical Music and Theater Major. Reddish-brown hair and brown eyes. Member of BUB. Smiles often and is kind.

Male, 19 years old, Applied Music. Brown hair and black eyes. Member of BUB. Sly and very playful.

Male, 17 years old, Applied Music. Light blue hair and pink eyes. Member of BUB. Often indifferent but smiles well.

Male, 19 years old, Applied Music. Pink hair, black eyes. Member of BUB. Sharp-looking but smiles quite a bit.

Female, 18 years old, Applied Music, Dance Major. Very jealous; gets annoyed and tries to steal things if she isn't number one. Long wavy brown hair and brown eyes.