マンモス潜函 (1957)

The film is a promotional film, recording the construction of a pressurized lockbox at the Hachinohe power plant in Aomori. Matsumoto's official first directorial debut at the Shinriken Motion Picture, the film found a 16mm film print stored in a civil library and digitized. His official credit is the assistant director in Silver Ring, commonly known as Matsumoto's first work. Matsumoto challenged to objectively capture the image of the worker in camera in spite of the limitations of promotional films where the records of the construction site were prioritized.