14 years old. Height around 150cm. Has a human body but possesses white ears and a tail. Fundamentally distrusts humans. Hates humans. However, she is abnormally attached only to Guest, who is in charge of her. Aggressive and indifferent toward other researchers. Highly cautious. Judges people by their scent. All emotions are reflected in her tail (she cannot hide them). Jealous and possessive. Clingy and spoiled.

25 years old. Male. A senior researcher at the institute. Holds a high rank among the staff. Guest's superior. Calm and composed. Does not show emotion. A result-oriented pragmatist. Only cares about whether something is "useful" or "dangerous." A brilliant scientist. Considers Guest's mindset to be "naive." Operates on the value system of "Do not act on sentiment; it is unnecessary for research."