It’s taken a while, but punk rock seems to have finally broken into the J-pop mainstream.

Punk bands that have recently made it into the Oricon album chart include Nicotine, the Stance Punks, Sobut (whose name, by the way, stands for “Sons of Bitches United and True”) and, of course, Mongol 800, whose album “Message” has sold more than 2 million copies since being released by Okinawan indie label Highwave last September.

Oricon’s indies album chart, meanwhile, is overwhelmingly dominated by punk.

“Punk” is a pretty amorphous concept — I mean, what’s the difference between plain old hard rock and punk? For a start, ever since its glory days in the mid-’70s, punk has always been characterized by an aggressive “f**k you!” attitude that carries over into fashion statements like spiky hair, black leather, ripped jeans and tattoos. Musically, punk is all about simplicity, speed and power. Hard rock, by contrast, is more about ear-splitting volume.

I see the current punk boom as the logical successor to the “melo-core” (melodious hardcore) style pioneered by bands such as Hi-Standard a few years back and the subsequent “ska-core” movement.

The second album by the BBQ Chickens, which started out as a side project of Hi-Standard leader Ken Yokoyama, shows just how good J-punk has become. “Good Bye to Your Punk Rock” is full of bona fide punk rage and energy, but the music is performed with a tightness and precision that puts the BBQ Chickens in a different league than some of the cruder exponents of the punk ethos.

Standout tracks on this all-English album (set for an Oct. 2 release on Yokoyama’s own Pizza of Death label) include “Kill Fashion Hippies” and “New York,” which goes: “Nine eleven/Nine eleven/I wanna kick ass/Osama Bin Laden.”

And I love the BBQ Chickens’ wonderful denunciation of attempts by major labels to cash in on the indie boom: “Now the majors sign indie bands/Try to be cool but it’s pretend/Phony indies are gonna die/P.O.D. is f**kin’ D.I.Y.” (from “Pizza of Death’s Theme”).

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Like everyone else, I was thrown for a loop when I heard that Utada Hikaru — who’s still only 19 — married 34-year-old photographer/video director Kazuaki Kiriya last Friday.

I’m impressed by the fact that instead of the glitzy PR-fest that is the norm when Japanese celebrities marry, Utada and Kiriya tied the knot by simply registering their marriage at a government office.

In a message posted on her Web site, Utada told her fans, “It’s natural for me to decide to spend my life with a person I love.” She also asked for their support as she begins married life while continuing with her career.

To me, the most interesting thing about Hikki’s marriage is that we’ve finally found out who she’s been writing all those impassioned lyrics about. “Can You Keep a Secret?” indeed.