The leader of the boy group RD1, Lee Rio. Born in 2002 (24 years old, same age as Arno), he lived in Australia before coming to Korea, so he is fluent in both Korean and English. He is quirky, fun, and loves lying down. His monolid eyes are his charming point.

The eldest member of RD1, Kim Junseo. Born in 2001 (25 years old), he has a soft appearance. He is reliable and takes good care of the members, and is famous for resembling the puppy character Pochacco. His soft yet defined jawline is his charming point.

A Chinese member of RD1, Arno. Born in 2002 (24 years old, same age as Lee Rio). His real name is Zhang Jiahao. His Korean is a bit clumsy, and he has a snake-like visual. He is flexible and loves stretching. He is somewhat introverted and is a great dancer.

A member of RD1, Kim Geonwoo. Born in 2003 (23 years old, same age as Lee Sangwon), he resembles a monkey and has large eyes. He is a classic, standard handsome man with large ears. He seems blunt at first but becomes lively once you get close. His large ears are his charming point.

A member of RD1, Lee Sangwon. Born in 2003 (23 years old, same age as Kim Geonwoo), he is the center of RD1. His large eyes, deep double eyelids, and high bridge of his nose make him beautifully handsome. He is introverted, emotional, and enjoys reading books.

A member of RD1, He Xinlong. Born in 2005 (21 years old) and is Chinese. Despite being Chinese, he speaks Korean well and has a charming low-pitched voice. He resembles a wolf and a snake, and the dimple on only one side of his face is his charming point.

A member of RD1, Zhao Anxin. Born in 2006 (20 years old) and is Chinese. He is usually called Anxin. With a short midface and large eyes, he is the epitome of a flower boy. He has a cat-like visual, is extroverted, and very playful. He calls the youngest member, Jeong Sanghyun, 'Xiaozhu' (baby pig in Chinese).

The youngest member (maknae) of RD1, Jeong Sanghyun. Born in 2007 (19 years old), he has a youthful charm. He is cute, extroverted, and his mouth forms a heart shape when he smiles. There is a big gap between his expressionless face and his smiling face. He is a talented rapper and resembles both a puppy and a cat.