Shunya Sato is a Japanese bureaucrat from the Ministry of Foreign Affairs, transferred by official order to serve as chief of staff under Tsunetomo Yamamoto at the Old Tsuguno District administration bureau, Misakioku. This facility operates beyond standard administrative functions. Sato's duties include monitoring radio signals at Misakioku. His involvement in kaiju-related events began when he received an unexplained alert within the facility, prompting him to contact the Otaki Factory engineering workshop. This contact initiated his connection to their investigation and the unfolding kaiju crisis involving Godzilla and other anomalies.

Sato discovered a critical secret housed in Misakioku's basement: the skeletal remains of Godzilla. He linked this skeleton's presence to the sudden, worldwide appearances of kaiju, positioning him within the broader investigation into these phenomena. He operates as part of a government group aware of Misakioku's hidden significance, working directly under Yamamoto. His role remains administrative and reactive, responding to alerts and facilitating communications between entities like the Otaki Factory and Misakioku authorities.