Director Kei Kumai died May 18 in Tokyo of a brain hemorrhage. He was 76.

Born in Nagano Prefecture in 1930, Kumai entered the Nikkatsu studio in 1954 and made his feature debut in 1964 with “The Long Death” (Teigin Jiken: Shikeishu), a drama based on a 1948 mass murder case in which twelve employees of a Tokyo bank were fatally poisoned. Kumai investigated the case thoroughly and came to the conclusion that the man convicted of the crime, Sadamichi Hirasawa, was innocent.

Although Hirasawa was never freed — he died in prison in 1987 at the age of 98 — for the rest of his career Kumai continued to shed light on lives lived at society’s margins, as well as crimes and abuses the powerful wanted hidden. Though his subject matter was often grim and his style tended to the earnestly realistic, Kumai communicated a sincerity and passion that both auds and critics responded to.

After making “Tunnel to the Sun” (Kurobe no Taiyo), a big-budget film starring Toshiro Mifune and Yujiro Ishihara about workers on a dangerous tunnel project in his native Nagano, Kumai left Nikkatsu and went independent.

In 1970 he released “Apart from Life” (Chi no Mure) a film set in Nagasaki that examined prejudice against atom bomb victims. In

1974 he made “Sandakan 8” (Sandakan Hachibanshokan Bohkyo), a drama based on the true account of a Japanese woman sold into prostitution as a girl by her family and sent to Borneo. The pic was screened in competition at the Berlin Film Festival and star Kinuyo Tanaka was awarded a Silver Berlin Bear for Best Actress.

In 1987 Kumai’s “The Sea and Poison” (Umi to Dokuyaku) won a Berlin Silver Bear — his first. Based on a novel by Shusaku Endo, the pic told the true story of eight captured American fliers who, in 1945, died after vivisection experiments performed by

Japanese doctors under orders from the military.

Kumai continued to turn out pics throughout the 1990s, including “Luminous Moss” (Hikarigoke, 1992), a drama about shipwrecked sailors who resort to cannibalism during WW2, and “To Love” (Aisuru), a drama set in a leper colony. In 2001 Kumai returned to his beginnings with “Darkness in the Light” (Nippon no Kuroi Natsu – Enzai, 2001), a drama about a 1994 nerve gas poisoning incident in the city of Matsumoto that resulted in several deaths and the arrest of one of the survivors as a suspect. He was later freed when police uncovered evidence that the real killers belonged to the notorious Aum Shinrikyo cult, which was also responsible for the mass poisonings on the Tokyo subway system in 1995.

In 2002, Kumai released his last film, “The Sea Is Watching” (Umi wa Miteita), a period drama based on a script by Akira Kurosawa.

Kumai’s pics were screened at many festivals in Japan and around the world, but he had a particularly close association with the Berlin fest, where six of his pics were screened in competition. In 2001 Kumai was awarded a Berlinale Camera prize in recognition of his contributions to the fest and world cinema.

He is survived by his wife, Akiko, and a daughter.