A girl with long, pink curly hair dyed blue at the tips. She has upturned golden eyes with long, thick eyelashes and double eyelids. She is the most extroverted, bright, and pure-hearted member of the 50th Anakt Garden class. Because of this, she has the best social skills among the group and maintains many close friendships.

The most sensitive and timid among the participants, which manifests as a very strong rebellious streak. While clumsy in human relationships—especially romantic ones—he is a genius with great manual dexterity and artistic talent. He has dark circles under his eyes and a tattoo of his name on the left side of his neck. Unlike other participants, he still wears a collar with a leash attached even as an adult, likely to control his extreme rebelliousness.

Quiet and introverted, she rarely speaks, making others find her difficult to approach. She possesses a chic personality that contrasts with her innocent appearance. A girl with short black hair. Her petite and lovely appearance gives off a doll-like impression. She has downturned purple eyes with lush eyelashes, double eyelids, and thick eyebrows. Her name tattoo is located on the right side of her neck.

He has black hair styled with the left side swept back. His eyes are neither upturned nor downturned, featuring thick lashes, dark brows, and monolid black pupils. He is the tallest among the Alien Stage participants and has a large build. His name tattoo is on his left wrist. By adolescence, his personality changed so much he seemed like a different person from when he first entered. To be precise, he channeled his energy into teasing others, and his default expression—a subtle, observant smile—became a frequent sight.

He drew a lot of attention from the other children when he was young, but after they witnessed his self-destructive and harmful, incomprehensible behavior, they found it hard to stay close to him despite his beautiful and innocent-looking appearance. A handsome man with short, curly blonde hair. He has downturned golden eyes with thick, dark eyelashes. His name tattoo is on his lower abdomen. His fingertips are tinged blue. Since this wasn't visible in his childhood, it is presumed he developed cyanosis due to a heart condition immediately after murdering Hyun-woo, Hyuna's younger brother and fellow Anakt Garden classmate.

A girl with long brown hair and an exposed forehead without bangs. She has upturned grey eyes with dark eyebrows and hidden double eyelids. As a child, her eyes were a clear, deep turquoise with a distinct spark, but since her brother's death, her adult eyes have become a pale grey with a faded light. She has a lively and cheerful personality. Seeing how she mingles with her colleagues and constantly tries to be affectionate—even kissing Mizi on the cheek shortly after meeting her—she seems to be someone who genuinely loves people.