A native of Tochigi Prefecture and a graduate of the University of Tokyo, where he majored in religious studies, Kazuhiro Soda took an early turn off a conventional career path when he went to New York in 1993 to study filmmaking at the School of Visual Arts. After a stab at fiction filmmaking, which won him prizes but not many job offers, he began working on documentaries to pay the rent — and discovered a new vocation.

But this admirer of Frederick Wiseman — a pioneering American documentary filmmaker whose observational style did away with talking heads, voice-over narration and background music — was never going to be happy grinding out documentaries for NHK, for whom such methods were de rigueur. After making more than 40 programs for the public broadcaster, Soda decided to strike out on his own.

He found a subject in a former University of Tokyo classmate named Kazuhiko Yamauchi, who was running for Kawasaki city council under the banner of the Liberal Democratic Party in 2005. Soda followed Yamauchi with his camera for two weeks, recording this coin and stamp dealer with no previous political experience being schooled in the arcane rituals of Japanese politics, including the prescribed way to shout his name to passersby. The resulting documentary, “Senkyo (Campaign),” was both funny (Yamauchi being something of a natural, if not always intentional, comedian) and revealing of the election process here in ways that TV news shows and documentaries, focused on winners and losers, rarely are.

Buoyed by the success of “Campaign,” which won honors and invitations from festivals abroad, Soda made more documentaries in the same observational, on-the-fly style, including 2008’s “Seishin (Mental),” which focused on a small clinic for the mentally ill, and 2010’s “Peace,” whose subject was the disabled and those who care for them, including Soda’s own in-laws. Then in March of 2011, he learned from Yamauchi’s blog that his friend was planning another campaign for city council, after being squeezed out of his seat by the bigwigs he had been assiduously cultivating.

“At that time I was showing my movie “Peace” at the Hong Kong (International Film) Festival and I didn’t have my equipment,” Soda tells me in fluent English at the office of his Japanese distributor, looking appropriately (for a filmmaker who spends long hours outdoors roaming the streets) tan and fit. “Then I decided to shoot, so I came back to Tokyo and bought new equipment and went to Kawasaki to film.”

As this comment indicates, Soda’s byword is spontaneity, not study. “I always try to have the minimum preconception about the subject and try my best not to know about the subject,” he explains. “Knowledge is always binding you — if you have certain knowledge about the subject, it becomes a preconception. It makes it harder to discover something totally new.”

This filmmaker-as-blank-slate method has its risks, however, as Soda discovered when Yamauchi decided to do a minimum of campaigning, leaving him with little to shoot of his ostensible subject. Soda, though, kept filming anyway.

“I’ve always said that if you look closely enough, you always discover something,” he says. “You have a movie, no matter what. That’s always been my theory, but I was tested by this film, because (Yamauchi) was not doing anything. … So I decided, OK, let’s just shoot and see what happens.”

Soda found a rich vein of material in the other candidates, as well as confrontations when two candidates backed by the LDP told him to take his camera elsewhere, which Soda flatly refused to do. “They were claiming ownership,” he comments. “They think it’s their campaign, so they can say things like, “OK, you can shoot, but you can’t. But it’s a public event, a public process.”

While refusing to buckle to the LDP candidates and their lawyers, who sent him a letter warning him not to use the footage, which he ignored (“If they create a fuss, it becomes publicity for the film,” he says with a smile). At the end of the campaign Soda was baffled by what he had filmed.

“I had a sense that I shot something very weird, very strange. I can’t really verbalize it.”

After delaying the start of editing for more than a year, until he had begun to forget the entire project, Soda was roused into action by triumph of the LDP, led by current Prime Minister Shinzo Abe, at the polls in December 2012.

“To me the result was strange, since there had been a nuclear accident and the LDP had been the biggest promoter of nuclear energy,” he explains. “So if they lost the election, it would have been logical, but they won big time: a landslide victory. This strangeness reminded me of the strangeness I felt shooting “Campaign 2,” so I got inspired and started editing.”

What he had, Soda realized, was not just a film about a political campaign, but a document of the national mood immediately after the Great East Japan Earthquake and tsunami of March 11, 2011.

“In a sense, the nuclear accident was kind of a science-fiction situation,” he comments. “It’s almost like somebody from outer space is attacking the Earth. … In a science-fiction movie, people run away screaming from the aliens, but when I went to Kawasaki to shoot I saw people going to work, just like every day. They had masks on (to protect themselves from the radiation), but they still had a rush hour. Moreover, the election campaign was same as usual; nobody was talking about the (nuclear) issue.”

Except for Yamauchi, who made the abolition of nuclear power the centerpiece of his campaign — and lost badly. “Nobody paid attention to him; he almost looked like a weirdo, a total outcast,” says Soda. “But he was insane in a sane way.”

Despite Yamauchi’s antinuclear stance, which Soda admits that he “totally agrees with,” he denies delivering any sort of message in the film.

“It’s almost like sharing my personal experiences with my fellow countrymen and it’s up to them what to think and what to feel,” he says. “As a filmmaker I see myself as a pitcher, but the audience is the hitter, not the catcher. I’m throwing the ball, but I want them to hit it. I want see where it goes. That’s my enjoyment.”

For a chance to win one of five double passes to see “Senkyo 2” visit jtimes.jp/film. The deadline is July 5.