When I visited Tokyo as a tourist in 2005, I couldn’t believe how clean the city was. Even then in San Francisco, there was litter on the sidewalks, despite there being public trash cans every half block or so. In Tokyo, trash cans were few and far between (I had to walk blocks with a food wrapper in my pocket before finding a proper place to put it), yet the sidewalks were spotless.

The Oscar-nominated “Perfect Days,” a Japanese film made by German director Wim Wenders, gives us a clue as to why. The film is about an elderly public toilet cleaner named Hirayama (Koji Yakusho), whose dedication to his job is part of a fulfilling but lonely life. And lonely does not mean empty; here is a man who has made peace with his existence, feeling useful in a country where cleanliness is next to godliness. He treasures his daily random interactions with people, his regular visits to his favorite eating spots, and a home life of reading and caring for his houseplants.

Hirayama is also a huge 1960s and ’70s music fan. As he drives between locations, he plays cassette tapes of songs by Patti Smith; Van Morrison; Otis Redding; Japanese-born folk singer Sachiko Kanenobu, a longtime resident of Glen Ellen, near Sonoma; and, of course, Lou Reed, whose “Perfect Day” suggests the film’s title. There are even two versions of “House of the Rising Sun”: the 1960s Animals hit played in Hirayama’s car and an impromptu cover sung in Japanese to him by his favorite matronly bar hostess, whose shop serves as a safe haven for lonely old men. It’s a great soundtrack.

Wenders, a major figure in the New German Cinema movement of the ’60s and ’70s, is a cinematic wanderer, whose films take audiences from Germany (“The American Friend,” 1977; “Wings of Desire,” 1987) to the American South (“Paris, Texas,” 1984) and around the globe (“Until the End of the World,” 1991) and back (most recently with “Anselm,” the 3D documentary about German artist Anselm Kiefer that opened in the Bay Area last month).

He has said “Perfect Days” is his tribute to Yasujiro Ozu (1903-63), whose characters were keenly rooted in the present but always aware of the passage of time. Wenders even chose to shoot his film in the square aspect ratio associated with Ozu’s films.

Wenders structures the film episodically, so characters, such as a goofy co-worker, a homeless man and a suddenly appearing relative, come and go from Hirayama’s life. Thus the story relies on Yakusho to carry this movie, and that he does.

Yakusho, now 68, was that guy who was seemingly in every Japanese film that made it to America a generation ago (“Tampopo,” 1985; and “Shall We Dance?,” 1996), and briefly crossed over to Hollywood in “Memoirs of a Geisha” (2005) and “Babel” (2006).

In “Perfect Days,” he delivers a great, heartfelt late-career performance, which won him the best actor award at Cannes Film Festival last year. His Hirayama is a shy, introverted man who goes long stretches without talking, just reacting to the world around him, yet intimately involved in the world around him. Yakusho’s face suggests so much, it’s impossible not to be drawn into his thoughts.

“The world is made up of many worlds,” he says. “Some are connected, and some are not.”

A word about the bathrooms that Hirayama cleans: They are exquisite, as if designed by the world’s best architects. Some have elaborate stone and steel designs; some have clear glass in which one can see the toilet and sink behind the glass, until someone locks the door, and the glass turns into a colorful green or magenta shield for privacy.

They’re much fancier than the million-dollar-plus Noe Valley toilet expected to open in April. Something tells me that the Japanese have this down, and that despite the museum-worthy designs, each of the toilets in “Perfect Days” was much more cost-effective.

Reach G. Allen Johnson: ajohnson@sfchronicle.com