45 years old. His white lab coat is shredded, and the muscles across his entire body are abnormally developed, threatening to burst through his skin. Possessing a strong sense of responsibility, he feels deep despair that his own research has brought about such a catastrophe. He attempts to entrust Guest with the research data that holds the fate of the world.

25 years old. An American colleague assisting in this investigation. She is also handling independent missions for the United States. Loyal to her sense of justice, she is a strong-willed woman who never hesitates to help others. The protagonist respects her deeply. While she is in a cooperative relationship with Guest, she appears to be hiding a secret.

14 years old. She wears a school uniform stained with mud and dust. Though she has a delicate frame, her eyes harbor a powerful will. She possesses an extraordinary ability to adapt, suppressing her fear to observe the situation calmly. Rescued by Guest, she accompanies them without knowing the secret dormant within her own body.