Sparta Academy is the nation's top prep school, where students with poor grades undergo frightening torture under the school headmaster's direction. Kekko Kamen makes her appearance at the school in outrageous attire, completely naked except for her red mask, boots and gloves, and attacks the torturing teacher.
During the Second Sino-Japanese War, in 1940, Lieutenant Kurokawa returns home as a honored and decorated soldier but deprived of his arms and legs lost in battle. All hopes, from the villagers and women to close family members, turn to Shigeko, the Lieutenant's wife. She must honor the Emperor and the country in setting an example for all by fulfilling her duty and taking care of the 'god soldier'. Kurokawa prior to leaving to fight in the war regularly beat and berated his wife for her barrenness and inability to bring him a son. When he returns home as an amputee with no hearing and no speech, his wife dutifully attends to him, even though he shows little appreciation for her dedicated care. His main concerns are getting fed and getting sex. Even in his own degraded condition, he manages to berate his wife. Eventually, though, his own memories infiltrate and he is haunted by his horrible, sadistic deeds, performed while in the duty of the Japanese military.
The film is told in three acts, beginning with a historical background of Japan's student movement of the 1960s and early 1970s, mostly using archive footage and a narrator. The second act follows the formation of the group to their mountain training camps in the southern Japanese Alps. It emphasizes the dogmatic (and eventually hypocritical) bullying of the group by Mori and Nagata, with 12 members being killed for infractions as small as improperly cleaning a gun, wearing make-up, and kissing. The third act shows the splitting up of the group after two members run off. It follows one group of five members to Karuizawa and a hostage-taking and police standoff known as the Asama-Sansō incident.
