At the heart of Chukiren 's mission was exposing the foolishness of war , especially through testifying to the things that they themselves did in the war and on the battlefield . They were known for being very active in testifying about and cooperating with witnesses of things such as Unit 731 , forced labor recruitment of Koreans , comfort women , and the Nanking Massacre . Because of this , many of the returnees ended up being branded as " red " regardless of their personal beliefs and experienced mistreatment in post-war Japan
Unit 731
Unit 731
Association of Returnees from China