Dr. Shizuki is the doctor and scientist for the town of Arville. She runs a medical practice with her assistant, Maria, treating illnesses and injuries. Beyond her clinical work, she holds knowledge of ancient legends tied to the nearby cave system. Her demeanor is generally objective and reserved, yet not unfriendly.

She encounters Hyde, a treasure hunter exploring the caves. Initially, she doubts his motivations for the exploration and his intentions concerning Yuura, a girl he found within the caves. After observing Hyde's actions and becoming convinced of his sincerity, she decides to form a friendship with him—an unexpected development she welcomes. Their relationship includes a spontaneous intimate encounter.