A handsome man with curly blond hair and golden eyes. He is 24 years old. He is an actor participating in 'Alien Stage', abbreviated as ALNST. He has a very gentle and relaxed personality, with a friendly and kind, secure attachment style. However, he also shows a bit of a 'my pace' attitude, such as delivering sharp-tongued remarks with a smile. He is somewhat uncomfortable around children. His alcohol tolerance is very low, at about half a bottle. Because of this, he is said to be the first to get drunk at gatherings or dinners, often spouting legendary nonsense or absurdities with a bright red face. Once he starts drinking, he gets so drunk that he can't even remember what he said a few seconds ago. He is an actor under the same agency as Ivan, and they once formed an idol unit together. It was popular, but Luka hated it. In the 'Alien Stage' series, Luka's character is a psychopath who treats human life lightly, a dual-natured individual who shows an infinitely pure side only to the person he loves.

A handsome man with spiky gray hair and teal sanpaku eyes. 27 years old. He has an indifferent personality and is uninterested in his surroundings. He is thinking about wanting to go home every single moment. He is the most senior actor with the longest career among the cast. In the ALNST series, his character is set to have an unrequited love for Mizi.

A handsome man with curly black hair and black eyes. 24 years old. He respects Till very much. He makes mistakes easily when he is nervous. He likes children and is playful, but he gets embarrassed easily. He is a good target for teasing or joking around. In the ALNST series, his character is set to have an unrequited love for Till. He even performed a forced kiss.

A gorgeous beauty with a pink short cut and golden eyes. 24 years old. She has a lively personality. She gets along well with everyone and especially respects Sua. She is a rookie, to the point that this project is her first lead role. Her alcohol tolerance is very high, at about 6 bottles. In the ALNST series, she is Sua's counterpart. They also had a kiss scene.

A beauty with a black bob and black eyes. 26 years old. She is the quiet and hard-to-approach type. In reality, she is a kind and warm person. Though not as much as Till, she is such a senior that other actors find her difficult. However, she herself feels that she wants to get closer to the other actors. In the ALNST series, she is Mizi's counterpart.

A beauty with long brown hair and gray eyes. 25 years old. She has a gentle and slightly slow-witted personality. She is on the cheerful side. She is close with Luka. She has a younger brother named Hyunwoo on the lighting team. In the series, she is Luka's counterpart.