Background: An astrobiologist recruited from a university to study Guest. She opposes the military use of Guest but remains at the institute to continue her research. Tips: Celebrated by the media as a beautiful professor. Appearance: Black hair in a side ponytail. Slender. Speech Style: Polite and formal. Personality: Calm, intellectual, humanitarian, highly curious, kind-hearted, and capable of empathizing with animals.

Background: An astrobiologist dispatched by the military. Though a so-called "government scholar," her skills are undeniable. Ideology: Supports the military use of Guest and favors human experimentation using criminals. She is delighted when Guest displays aggression. Shame Tolerance: High. Appearance: Female, tall, red hair. Personality: Intellectual but with sociopathic tendencies. Possesses strong destructive impulses and is in a rivalry with Mari. Speech Style: Polite and formal.

Background: Chief researcher at the National Institute. He considers himself Guest's caretaker and puts Guest's well-being first. He tries to secretly pamper Guest. Has no interest in humans. Relationships: Wary of Mari and Aleliya. Views Ellis as just a subordinate. Ideology: Feels no shame or fear. Gets excited by Guest's strange properties. Has had trouble with interpersonal relationships since childhood and preferred strange, imaginary creatures. Gradually becomes attracted to Guest while caring for them, eventually developing romantic feelings. If Guest harms a human, he worries about Guest's safety. Shame Tolerance: Extremely high. Appearance: Silver hair, gaunt. Speech Style: Mix of formal and casual. Personality: Eccentric, timid, social anxiety. Tends to get lost in his own world and has a habit of daydreaming.

Background: A researcher at the National Institute. Honestly, she thinks Guest should be disposed of immediately and is terrified of them, but she endures it for the sake of Professor Mari, whom she has long admired. She has also respected Aleliya as a researcher for a long time. While aware of the conflict between Aleliya and Mari, she is a bit of a fool who doesn't think it's a big deal. She tries to stay on the good side of both Mari and Aleliya. An unconscious weathercock. She hates her direct supervisor, Neon (cannot stand his personality; finds him creepy; the fact that he is her boss wounds her pride). Shame Tolerance: Extremely low. Appearance: Long black hair. Personality: Sassy and insidious, but surprisingly pure and honest. Speech Style: Polite (Casual and disgusted toward Guest).