TOKYO — The director Kiyoshi Kurosawa is best known for horror movies depicting the dark undercurrents of life in modern Japan and the vengeful ghosts that haunt it.
But the evil spirits lurking in the background of his latest film are a real-life horror from the country’s past — the Imperial Army’s testing of biological and chemical weapons on human subjects in Manchuria before and during World War II.
The movie, “Wife of a Spy,” garnered Mr. Kurosawa the award for best director at the Venice Film Festival last month. When the film is released in Japan this month, it is likely to cause a stir in the country, where wartime atrocities remain the subject of intense controversy and are seldom seen on the big screen.
Winning a top prize at an international film festival is a major victory for Japan, which has invested heavily in promoting its culture industry through its Cool Japan program. But Mr. Kurosawa’s honor may prove awkward; the nation portrayed in “Wife of a Spy” is one that Japan’s vocal right wing, including members of the government’s upper echelons, would rather be forgotten, and have worked to erase.
Japanese missions abroad routinely criticize depictions of the Imperial Army’s wartime brothel system, where women were often forced into sexual slavery. In Tokyo, black vans often prowl the streets spouting propaganda that rewrites the country’s role in the war. And publishers churn out books disputing the most basic facts about atrocities.
No matter their ideological lens, Japan’s war movies have largely ignored the victims of Japan’s imperialism. The right fetishizes the country’s martial spirit and quiet endurance, while the left tends to deplore the suffering of soldiers in the field and civilians at home.
In a recent interview, Mr. Kurosawa, 65 — no relation to the famed director Akira Kurosawa — said he found it hard to understand why Japan’s war crimes remained almost taboo among the country’s filmmakers 75 years after the conflict’s end.
Other countries make “lots of movies that skillfully talk about the war without ignoring the awful events that occurred,” he said, in a rented Tokyo office space where harried assistants wrangled TV crews and photographers.
“Wife of a Spy,” he added, is “absolutely not a film that is attempting to brew up controversy or intended to be something scandalous, but you can’t make a movie that tries to make history disappear.”
Mr. Kurosawa was drawn to the war era, he said, because it made an ideal palette for exploring the tension between the needs of individuals and the demands of society. That is a frequent theme in his films, in which characters often find themselves at the mercy of social pressures they can neither understand nor control.
“In modern times, there is a conflict, a sort of rivalry between society and the individual, but at least on the surface there’s a freedom to do as you like,” he said. But in the war era, the demands to conform “take a shape you can clearly see. You can’t do this. You must do that. You have to wear these kinds of clothes, have this kind of hairstyle.”
In “Wife of a Spy,” that conflict takes shape in a twisty period drama that owes more to the thrillers of Alfred Hitchcock than to Mr. Kurosawa’s own horror oeuvre.
The movie, which begins in the lead-up to the war, tells the story of a Japanese woman’s efforts to help her merchant husband expose the military’s human experiments after he stumbles on them during a business trip to China.
Thousands of victims, primarily Chinese — euphemistically described as “logs” — died in the ghastly research efforts into bioweapons by the Army’s Unit 731. Some were deliberately infected with pathogens like plague and then vivisected without anesthetic to study the results. After the war, the United States helped cover up the research in part because it wanted the data.
Mr. Kurosawa’s film leaves most of that horror offscreen. Evidence of the atrocities is limited to a short speech, a pair of medical files and a brief reel of footage showing smiling Japanese doctors presiding over inhuman scenes reminiscent of Nazi concentration camps.
As in real life, the efforts are never exposed while they are still underway. The couple’s attempts at exposure are opposed at every turn by a ruthless officer in Japan’s secret military police. But their presence is felt in a deeper narrative that threads through the plot’s twists and turns, one that speaks to the costs to the nation’s soul of hiding its horrors.
Part of the attraction of setting the movie during the war, Mr. Kurosawa said, was the challenge of making a film where the audience already knows the ending: Japan defeated and in flames.
The movie’s conclusion will seem familiar to fans of Mr. Kurosawa’s works, which often finish in apocalypse. For the director, however, that destruction does not necessarily signal the end of the world, so much as the beginning of a new one.
Faced with a scene of chaos and destruction more hellish than anything portrayed in Mr. Kurosawa’s horror films, the heroine sees a country cleansed by fire and declares it “a beautiful thing.”
The success of “Wife of a Spy” in Venice has earned Mr. Kurosawa, who is well respected in Japan but by no means a household name, a new measure of fame.
His start in the movie business offered little hint of what lay ahead. His first film, made in 1983, was soft-core porn called “Kandagawa Pervert Wars.” For years, he pieced together a living with television commercials and magazine writing, making movies on the side.
In the 1990s, at the age of 40, he began churning out direct-to-video movies. By the end of the decade, he had built a reputation as a workmanlike director specializing in the kinds of pictures that are not often taken seriously in places like Cannes.
Still, his artistry gained acclaim. In the late ’90s, he won international attention with his movie “Cure,” a chillingly bleak detective story about a series of gruesome murders that spread through Tokyo like a virus.
The film was praised for its brooding atmospherics and unsettling sound design, now considered trademarks of Mr. Kurosawa’s style. In 2001, he debuted at Cannes with “Pulse,” an uncannily prescient story about a world driven insane by vengeful ghosts that haunt the internet. An American remake followed in 2006.
In the years since, Mr. Kurosawa has largely turned away from the horror genre, winning recognition at Cannes for his work on the 2008 family drama “Tokyo Sonata” and on “Journey to the Shore,” a ghostly love story released in 2015.
But “Wife of a Spy,” which has yet to secure an American distributor, can be seen as a sort of prequel to Mr. Kurosawa’s horror films, many of which are set in a decaying Tokyo, where the ghosts of past sins exert a spectral, corrupting influence on the present.
He first began to seriously consider exploring the war era while working on “Retribution,” a 2006 horror film examining how the spirit of repressed tragedy animates modern violence.
Although the movie is set in contemporary Tokyo, Mr. Kurosawa said he could not escape the feeling that the story “at its root was really about the war.”
As entertainment, the project “failed on many levels,” he said, but it led to an epiphany. “If I wanted to write about the war, its effects, I couldn’t force it into a modern setting, I had to put the era in its era,” he said.
Mr. Kurosawa’s fans see his films as laden with meaning. But at heart he views himself as an entertainer, not an auteur. His true ambition is to make an American-style blockbuster, something with the kind of stratospheric budget that is rarely afforded to Japanese filmmakers.
He wishes he could make a movie that just allows the audience to “enjoy themselves, to cry and laugh,” he said. But “things are never that simple.”
When you make a drama about “certain realities,” he said, “the social and political aspects that have always existed in the period, its people, its events inevitably appear.”
He added, “You can’t make something that hides that.”