The film opens with the passage " Friendship is friendship ; history is history . " A group of Japanese boys are conscripted into the Youth Corps . They are assigned to the Kwantung Army , and are brought to one of the facilities serving Unit 731 , which is headed by Shiro Ishii . Soon , they are introduced to the experiments going on at the facility , for which they feel revulsion . The purpose of the experiments is to find a highly contagious strain of bubonic plague , to be used as a last-ditch weapon against the Chinese population
Unit 731
Unit 731
Men Behind the Sun