With a layered sound that blends postrock dynamics and sprawling song structures with pure J-pop sensibility, akai ko-en is quickly becoming one of Tokyo’s most talked-about new bands. But just try searching for the group on YouTube and see how far you get.

Despite releasing its second mini-album last week through EMI, and though it toured in Canada last fall, akai ko-en has managed to maintain a near-zero-tolerance policy toward the Internet. And in an age where every band in the world wants you to check out its SoundCloud or Facebook page, the four-piece’s bid to build an air of mystery seems to be working.

“Once you open a door, people can see that the room isn’t very big — so you have to think carefully about when to open it,” explains guitarist Maisa Tsuno, who writes most of the songs and does most of the talking. “Once there’s some anticipation around us making an appearance online, that’s the time to do it.”

Hype is certainly building: Two years after the band was conceived, akai ko-en’s name is on the lips of opinion-formers throughout Tokyo’s music scene, thanks in part to its incendiary live shows — which for a time were the only place to find out what the band actually sounded or looked like. Until the release last week of “Tomei Nanoka, Kuro Nanoka” (“Is it Transparent, Is it Black”), the band’s music was unavailable to buy or sample online.

My first encounter with akai ko-en at a gig last year (after three separate people recommended them to me) was far from what I’d expected. Aged 19 and 20 (Tsuno is the oldest), the four girls have a way of building their songs from silence to a thrilling climax: They channel the dynamic intensity of Mogwai, the bass grooves of mid-era Radiohead and the skewed pop nous of Kaela Kimura.

Speaking to The Japan Times in a boardroom at EMI’s Tokyo office, singer Chiaki Sato, bassist Hikari Fujimoto and drummer Nao Utagawa seem painfully shy, a world away from their stage personae. “Playing live is so liberating,” proffers Fujimoto. “We can make a lot of noise without getting told off!”

“I don’t think about anything on stage apart from singing in tune,” laughs Sato nervously, before falling silent once more.

The band’s set at last weekend’s EMI Rocks all-day concert was a major triumph. Totally owning the cavernous stage at Saitama Super Arena, the girls pulled graceful balletic moves in white wispy dresses, before battering an audience of 16,000 with alternating waves of tender guitar, clashing rhythms, vocal-harmony breaks and all-out yet carefully controlled noise.

The idea to shun online promotion originally came from EMI, which had previously used a similar tactic with the band Soutaiseiriron. That band built a strong following despite refusing to be interviewed or photographed; it seems that EMI clung to the concept even after its relations with Soutaiseiriron dissolved (the band is now independent).

“We don’t avoid being seen altogether,” asserts Tsuno, the not-shy one, who points out that the band sometimes posts photos on Twitter. “You can see us when we play on stage. Besides, we’ll put some music and video on the Internet eventually.”

“We want to be the ones to decide when things start appearing online,” says Utagawa.

Which is all well and good — but, I point out, all it takes is one fan with a smartphone and a YouTube account and you’ve lost control of that timing. Right?

“That’s happened a few times, and EMI has had the videos taken down,” replies Tsuno. A look of uncertainty flickers across her face. “The people who shot those videos uploaded them because they like us,” she admits, “so I do feel bad about it.”

The young women each have radically different music tastes — from Pantera to Taylor Swift, through the epic sweep of John Williams and Nobuo Uematsu’s “Final Fantasy” game scores to 1980s and ’90s J-pop idols such as Pink Lady and Seiko Matsuda. The only artist they all agree on is Shiina Ringo — and even then the members are divided between fans of her solo music and of her band, Tokyo Jihen, with whom akai ko-en shared a stage at EMI Rocks.

Clearly Japanese music is a big piece of the puzzle. While the four-piece draws from postrock and prog, it’s always within the context of finely honed, concise pop structures. It’s beyond postpop: This is post-J-pop.

The band started out covering songs by Japanese guitar-driven pop acts Chatmonchy and GO!GO!7188, as well as the aforementioned Kimura and Tokyo Jihen, and began to write its own songs in spring 2010. The self-released CD “Walk With Bremen” followed last March.

Recorded at Gok in Kichijoji and at Tonemeister in Setagaya Ward, and produced by Tsuno, “Tomei Nanoka, Kuro Nanoka” collects the darker of the band’s material: “We played the songs with a black heart,” says Tsuno. It will be followed by another, “cuter” mini-album in May, conceived as a pair. “This one is black, and the next one will be white.”

While Tsuno harbors no great ambition to tour the world (America is “scary”), she does have one Internet-policy-related regret from the band’s Canada tour that she hopes to rectify someday.

“We didn’t take any CDs to sell in Canada, because we’d heard that Westerners upload music so quickly and we were worried about our music going online,” she says. “I wish we could have sold CDs at those shows though; I worry whether people will remember us. I want to go once again, with all our music already online and say, ‘Here we are!’ “

“Tomei Nanoka, Kuro Nanoka” is out now, with a release party at WWW in Shibuya, Tokyo, on April 6. For more information, visit www.akaiko-en.com.