Born in Hiroshima Prefecture, Mori graduated from Rikkyo University, where he appeared in the student films of Kiyoshi Kurosawa. After graduating, he tried acting and even appeared in Kurosawa's feature debut, the pink filmKandagawa Wars. He worked at other odd jobs before finally finding employment at a TV production company in 1989, where he began working on documentaries. While working freelance or under contract, he made a number of television documentaries before making A and A2, two documentary movies about the everyday life of Aum Shinrikyo followers. Aum Shinrikyo is a controversial Japanese religious group most known for its involvement in a series of incidents including the Tokyo subway gas attack. A showed at the Berlin Film Festival, and A2 won two prizes at the 2001 Yamagata International Documentary Film Festival. One particular scene from A, in which a plainclothes policeman attacks an Aum follower who is then arrested for attacking the actual attacker, sparked controversy among the audience watching the film. The footage was later introduced in court and the 'Aum attacker' was acquitted as a result. Filmmaker Mori was accused of staging the improbable incidents and using actors. Some even refused to believe the footage was shot inside the Aum facilities. When A2, Mori's second controversial film about the cult was completed, the filmmaker declared his unwillingness to return to the Aum theme in the future. By his own admission, the efforts invested in production of the two documentaries did not bring him anything more than financial damage and troubles, due to limited scale of theatrical screening and refusal of TV broadcasting corporations to licence the films. However, in 2010 he wrote a critically acclaimed book on the intervening decade of Aum entitled A3. While his documentaries on Aum Shinrikyo were very controversial when they were being filmed and shown, Mori is today considered amongst Japan's most talented independent non-fiction filmmakers. His most recent work, 311, is a collaborative work about the aftermath of the Tohoku earthquake. He has also published many books on social issues and the media.
