Yunbogi is a child who lives in a slum on the outskirts of Daegu, South Korea. Abandoned by his mother, Yunbogi must care for his two sisters and brother by taking on a series of small jobs.
Consisting of a series of diary entries narrated by a boy over photographs made by Oshima himself during a 1964 trip to Korea, Yunbogi's Diary is a highly political tale chastising Japan's involvement in Korea. With this shortfilm, Oshima confronts his country with the mess it made during the occupation, particularly the resulting chaos and poverty that would continue beyond the Korean War. Throughout the film, he draws parallels with the situation in Japan right after World War II. The diary entries and images come across as being equally representative of Japan in post-war years. However, at regular intervals the boy's narration is halted and Oshima's own voice is heard, reading verse that emphasises the fact that this is Korea in the 60s rather than Japan in the 40s, and that children are suffering most of all. And when children suffer, the future suffers. Oshima seems to suggest that the Japanese involvement has robbed this country not only of its dignity but also of its prospects.