Japan's public broadcaster NHK aired a documentary on Tuesday titled A Secret Unit: The Silent Postwar Era, revisiting the history of Unit 731 of the Imperial Japanese Army through historical photographs, archival records and testimonies from relatives of former members and witnesses.

The documentary features a personnel roster released by Japan's National Archives, interviews with relatives of former Unit 731 members, and personal artifacts, including surgical instruments brought back from the unit and documents expressing remorse.

It also includes testimony from former Unit 731 Youth Corps member Hideo Shimizu, who recalled the unit's strict secrecy, the destruction of evidence during its retreat, and his own involvement in collecting human remains.

Tokyo Chuo Ward Assembly member Yoshitomo Kawabata shared clips from the documentary on social media, saying attempts to erase or deny this chapter of history were "questionable and despicable," and that Unit 731 was one such example.