The theme of the film is based on the famous Takikawa Incident of 1933, which forced the resignation of Professor Yukitoki Takikawa from the faculty of Kyoto University for his supposed "communistic thought", and caused a sensation among the nation's intellectuals. One of his pupils was Hidema Ozaki, who became involved in the Sorge spy case, and was executed in Tokyo in 1944.

The film opens with the professor being relieved of his post. At first, his daughter does not realise the meaning of this. However, when a pupil of her father's, with whom she is in love, is arrested as a spy and executed, she begins to understand the kind of world she lives in.

She decides to take his ashes to his parents in the country, live with the peasants, and share their existence.