Tomoaki Onizuka joined the National Police Agency in April 1995 and retired in August 2022 as the Chief of the Nara Prefectural Police Headquarters. He spent much of his career in security and public safety, and foreign affairs divisions, working in the Security Bureau and Foreign Affairs and Intelligence Department of the National Police Agency, as well as the Public Security Bureau of the Metropolitan Police Department. He was involved in domestic extremist group countermeasures, operations against Aum Shinrikyo, investigations into North Korea’s abduction of Japanese citizens, espionage cases, and the illegal export of nuclear development-related materials. He also participated in joint operations with counterparts from the U.S. and other nations. In the Cabinet Intelligence and Research Office, he worked extensively in liaison roles aimed at strengthening cooperation with foreign counterparts and became well-versed in HUMINT, TECHINT, and OSINT intelligence activities. He served as Chief of the First International Division of the Cabinet Intelligence and Research Office and as a Senior Advisor at the National Security Secretariat, where he coordinated Japan’s intelligence community and addressed issues such as information protection through security clearance and economic security.