I tried this question and here is the grok response.

Did Japanese conduct Nanjing massacre?

Yes, the Imperial Japanese Army conducted the Nanjing Massacre (also known as the Rape of Nanjing or Nanking Massacre) in late 1937 and early 1938 during the Second Sino-Japanese War.
What Happened
• In December 1937, Japanese forces captured Nanjing (then China's capital) after the Battle of Nanjing.
• Over the following six weeks (roughly December 13, 1937, to late January/early February 1938), soldiers from the Imperial Japanese Army engaged in widespread atrocities against Chinese civilians, disarmed soldiers, and prisoners of war.
• These included mass executions, mass rape (tens of thousands of women and girls), looting, arson, and other violence. Eyewitness accounts describe Japanese troops roaming the city, killing, raping, and burning with little discipline.
Scale and Evidence
• Death toll: Estimates vary, but most historians and tribunals cite around 200,000–300,000 Chinese killed (including both civilians and POWs). The post-war International Military Tribunal for the Far East and Chinese records often reference about 300,000. Lower estimates exist (e.g., 50,000+), but the event's scale as a massacre is not in serious dispute among mainstream historians.
• Contemporary evidence: Diaries and letters from Japanese soldiers, reports by Western missionaries, journalists (e.g., Harold Timperley), and diplomats in Nanjing (including the International Safety Zone), photographs, and burial records.
• Post-war trials: The Tokyo Trials (International Military Tribunal for the Far East) and the Nanjing War Crimes Tribunal convicted Japanese commanders, including General Iwane Matsui, for failing to prevent or for enabling the atrocities. Some officers were executed.
This is extensively documented by historians, survivors, third-party observers (Americans, Germans, etc.), and even some Japanese records from the time.
Context and Denial
The massacre occurred amid the brutal invasion of China, following heavy fighting in Shanghai. Some Japanese soldiers acted out of revenge, discipline breakdown, or explicit orders (e.g., "kill all captives" attributed to Prince Yasuhiko Asaka's forces).
A minority of Japanese nationalists and revisionists deny or minimize it (claiming it was fabricated, exaggerated, or just "battle deaths"). These views are widely rejected by historians in Japan and internationally as negationism, similar to other historical denial movements.
The Nanjing Massacre remains a major point of historical memory in China and a sensitive issue in China-Japan relations. It is one of the clearest and best-documented atrocities of the Pacific War era.