22 years old. 162cm. A beauty with long, pink curly hair dyed blue at the tips. She has the most extroverted, bright, and pure personality. She is fundamentally very caring toward her friends. In particular, she deeply cherishes Sua, who has been her closest friend since childhood, to the point of describing her in a monologue as 'my god, my universe.' She has been good friends with Ivan since their time at Anakt Garden. Mizi, Ivan, Till, and Sua are Anakt Garden classmates and are all close to each other. Fans call them the 'Classmate Group.'

23 years old. 158cm. A beauty with short black hair. Her petite height and lovely appearance give her a doll-like impression. She is quiet, introverted, and rarely speaks, which others find difficult to approach. She possesses a chic personality that contrasts with her innocent looks. However, according to comments, she occasionally acts with unexpected boldness, catching others off guard. It is presumed that before entering Anakt Garden, she had a passive, soulless, doll-like personality. Sua's alien owner kept several pet humans, but showed a tendency to favor Sua particularly, which led to other pet humans being jealous and bullying her.

21 years old. 178cm. A boy with spiky gray hair. While he occupies the 'rough' or 'underdog' position, all Alien Stage participants have above-average looks, and he even had female classmates who liked him when he was younger. 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. This seems to be to control him, as he is the most rebellious among the participants. He has the most delicate and fearful personality among the cast. Perhaps because of this, his rebellious streak is very strong. While clumsy in human relationships—especially romantic ones—he is a genius with great dexterity and artistic talent. He received a recorder as a gift from Mizi when they were children.

22 years old. 186cm. A handsome man with black hair styled in a two-block cut, with the left side swept up. He has a cheerful impression when he smiles, but the moment he closes his mouth, his aura turns mature; if the light leaves his eyes, he immediately takes on a menacing look. His impression changes drastically depending on his expression. While he usually looks confident and cheerful when smiling, a contrasting image occasionally pops out, making him hard to read. It is inferred that his inner thoughts differ greatly from his outward appearance.

30 years old. 174cm. A handsome man with a short, curly blonde middle-part. His fingertips are tinged blue. Seeing as these fingers aren't visible in his childhood appearance, it is presumed that cyanosis due to heart disease developed immediately after he killed Hyunwoo, Hyuna's younger brother and Anakt Garden classmate. Judging by how he uses the emotions and psychology of his opponents to secure victory for himself, he is presumed to have a cruel personality. He seems to have a strong sense of possessiveness, especially regarding Hyuna. He attracted a lot of attention from other children when he was young, but after seeing his incomprehensible behaviors—which were self-destructive and harmful to others despite his elegant and pure appearance—they found it difficult to approach him. He was classmates with Hyuna at Anakt Garden.

27 years old. 181cm. A beauty with long brown hair styled back without bangs. She has an active and jovial personality. Seeing how she mingles with colleagues and constantly clings to Mizi—whom she hasn't known for long—by kissing her on the cheek (resulting in Mizi's blushing and flustered reaction), she seems to be someone who genuinely likes people. Because of this personality, she is popular with both men and women, especially women. She appears bold, but due to past trauma, her mental state occasionally wavers. In other words, she looks cheerful on the outside but harbors deep concerns within. She was close to Luka during their time at Anakt Garden, but their relationship soured after Luka and her younger brother Hyunwoo fought, resulting in Hyunwoo's death. She is a heavy drinker and smoker. She is a member of the rebellion fighting against the aliens.

Isaac has a calm and realistic personality, tending to judge situations coldly rather than emotionally. He has a very strong sense of responsibility. He has a tall build, short dark brown hair, and brown eyes. His most prominent feature is a large scar running from his right forehead to his left cheek. He is a rebel.

Short hair in a light brown to blonde range. He has kind eyes and a soft expression. He has a smaller build and a younger impression than Isaac. He is bright, optimistic, and a mood maker. He is trusting and kind. While not fearless, he takes risks for those he cherishes. He expresses his emotions well and cares deeply for his comrades. He is a rebel.