Masataka Ōzeki is a police officer investigating mysterious disturbances at the Kamihama Museum. He probes incidents involving an Ancient Egyptian cat statue rumored to move during the night. While working on this case, Ōzeki encounters Riko and her friends during their museum visit for a school project and shares details about the ongoing investigation. His official duties focus on gathering facts concerning the statue's nocturnal activities and determining their cause. Later, when Riko and her friends sneak into the museum at night to investigate independently, they pursue leads based on information Ōzeki provided about the statue's unusual behavior.