Way back in the 1990s, when the “Cool Japan” campaign was but a faint, distant blip on the nation’s radar, a synth-pop group called Denki Groove was doing its best to represent Japanese “cool.”

Founded in 1989 by friends Takyuu Ishino and Pierre Taki — who both hailed from the city of Shizuoka — Denki Groove initially came across as a Yellow Magic Orchestra rip-off (or tribute). But after the mega-success of the album “Vitamin” in 1993, Denki Groove officially came into its own.

More than 20 years on, the duo continues to enthrall techno fans in Japan and Europe — particularly in Germany. Now in their late 40s, Ishino and Taki released a single earlier this year titled “Fallin’ Down.”

But Denki has never been much for conventional self-promotion, so it comes as a surprise that the pair agreed to be the subject of a documentary with the slightly ambivalent title of “Denki Groove The Movie?” Apparently, Ishino asked filmmaker Hitoshi Ohne (“Bakuman,” “Moteki”) to take up the project. But later when Ohne followed up about the film, Ishino acted as though he “knew nothing about it,” the director says.

“That’s not surprising though, those two never give a straight answer to anything,” Ohne tells The Japan Times. “I thought, ‘Yeah, well … that figures,’ and I just got to work.”

The documentary features over two decades of Denki Groove history, interviews with former members Yoshinori Sunahara and Arashi Takahashi, among other notables, and clips from the famed press conference in which Ishino and Taki appeared fully nude to “commemorate” the departure of Takahashi from the group. The documentary opened in Japan on Dec. 26 and plays for just two weeks.

“Maybe it will get a longer life span, who knows?” Ohne says. “With Denki Groove, you can never tell what will happen.”

Ohne has been following the group for many years and says that when he first heard its sound in the early ’90s, it gave him “a window onto another world and another market.”

“These guys were going overseas and actually selling their stuff to a very enthusiastic audience in Europe,” he says. “That seemed really cool to me.”

Ohne adds that Japan is blessed with a huge domestic music market.

“It’s easy to be satisfied with just being popular here. There’s no real need to go abroad,” he says. “And everyone knows that what works in Japan, doesn’t necessarily work overseas. But Denki Groove never showed fear about taking their music out of Japan, and by doing so they made it clear they weren’t interested in being celebrities here or hitting No. 1 on the Oricon Chart or any of that stuff. To put it simply, they were too cool for that.”

However, the landscape has changed. Making it here now carries as much weight as making it elsewhere. Ohne says it’s Denki Groove’s longevity that impresses him the most.

“Also, Japanese music fans are so loyal — they stick with their chosen bands throughout their careers.”

Denki’s hard-core followers may find this documentary a little too familiar and Ohne admits he meant it to be accessible to those who are not fans as well.

“It’s really an introductory course to the world of Denki Groove,” he says, “and as such, the younger generation can see how cool these old geezers were, back in the glorious ’90s.”

“Denki Groove The Movie?” is playing in select cinemas. For details, visit www.denkigroove.com/themovie.