Best known for his writing collaborations with directors Kōji Wakamatsu and Nagisa Oshima, often under the pseudonyms "Izuru Deguchi" or "De Deguchi" (出口出), he also directed a number of his own films, usually dealing with left-wing political themes.

[1] He stopped making films in the early 1970s and joined the Japanese Red Army.

[2] He resided in Lebanon for 28 years, lending assistance to the Popular Front for the Liberation of Palestine until he was arrested and extradited back to Japan in 2000 due to his connections to the JRA.

[3] Adachi directed Revolution+1, a film based on the assassination of former Prime Minister Shinzo Abe in 2022, focusing on a fictionalized version of the suspect Tetsuya Yamagami.

[4][5] On September 27, the day of Abe's state funeral, a special 50-minute version of the film was shown in small theatres across Japan.