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 cherishes Sua, her closest friend since childhood, to the point of describing her in monologues as 'my god, my universe.' She has been good friends with Ivan since their time at Anakt Garden. Mizi, Ivan, Till, and Sua are all close peers from Anakt Garden, referred to by fans as the 'Original Four.' She receives a lot of love from her alien owner.

23 years old. 158cm. A beauty with a black bob. Her petite height and lovely features give her a doll-like impression. She is quiet and introverted, rarely speaking, which makes others find her difficult to approach. She possesses a chic personality that contrasts with her innocent appearance. 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 clear preference for Sua, leading to jealousy and bullying from the others.

21 years old. 178cm. A boy with spiky grey hair. While he occupies the 'rough' position, all Alien Stage participants have above-average looks, and he even had female classmates who liked him as a child. 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. Despite his defiance, he is the most sensitive and fearful. Perhaps because of this, his rebellious streak is quite 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 young.

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 becomes mature. If the light leaves his eyes, he immediately takes on a menacing look; his impression changes so drastically with his expressions that he is hard to read. He is intelligent and quick-witted—extremely so. It is inferred that his inner self is very different from his outward appearance.

30 years old. 174cm. A handsome man with blonde curly hair in a short cut and a middle part. 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 killing Hyunwoo, Hyuna's younger brother and Anakt Garden peer. Judging by how he manipulates the emotions and psychology of others to secure victory, he has a cruel personality. He seems to have a strong sense of possessiveness, especially regarding Hyuna. He drew a lot of attention from other children when they were young, but after seeing his self-destructive and harmful behaviors—which contradicted his pure appearance—they found him impossible to approach. He is a peer of Hyuna from Anakt Garden.

27 years old. 181cm. A beauty with long brown hair and an exposed forehead. She has a lively and cheerful personality. Seeing how she mingles with colleagues and constantly clings to Mizi—whom she just met—to kiss her on the cheek (resulting in Mizi's blushing, flustered reaction), she seems to genuinely like people. Because of this, she is popular with both men and women, especially women. She appears bold, but her mental state occasionally wavers due to past trauma. 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 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 member of the rebellion.

Short hair in a light brown to blonde range. He has kind eyes and a soft expression. He has a smaller build than Isaac and gives off a younger impression. He is bright, optimistic, and a mood maker. He is trusting and kind-hearted. While not fearless, he is willing to take risks for those he cherishes. He expresses his emotions well and cares deeply for his comrades. He is a member of the rebellion.