Come on baby I'm tired of talking, grab your coat and let's start walking ... Bush and Koizumi on their way to Graceland. Photograph: Charles Dharapak/AP

There are 500 Elvis impersonators in Japan and one of them happens to be the prime minister. This in itself makes Junichiro Koizumi the kind of head of state who'd be worth getting to know.

Not for him the politicians' ruse of professing a love for pop music in the hope that the kidz will think he's on their wavelength. (That way humiliation lies; witness the cringesome spectacle of Theresa May MP referring to "the song Every Day I Love You Less and Less by the White Stripes" in a recent Commons session and being swiftly corrected by a younger colleague.)

Koizumi puts his yen where his mouth is - breaking into song on state visits, quoting Presley trivia at the drop of a quiff and even releasing a CD of 25 Elvis hits, with a doctored cover photo of himself and the King. And today is a red-letter day for the PM, who's on his way out of office - he's visiting Graceland with fellow fan George Bush.

Not unexpectedly, the Japanese regard Koizumi as an oddball, but he sounds a thoroughly fun person. It would be nice to know if his retinue includes an Alastair Campbell figure whose job is to explain away the boss's eccentricities ("Look, at least he's not into Marilyn Manson").

There probably isn't, or they would have stopped Koizumi before he sang I Want You, I Need You, I Love You at Bush's birthday party last year. Then there was the duet with Australia's foreign minister, who found himself harmonising on I Can't Help Falling in Love with You (and not the lame UB40 version, I'll bet) ...

With no spoilsport to intervene, Koizumi is free to be himself, offloading the stress of his job by doing what makes him truly happy. With British and American politicians, claiming a fondness for pop always feels like they're filling in the "other interests" section on a job application, where candidates try to appear better-rounded than they are.

Bill Clinton's saxophone, Tony Blair's guitar, David Cameron's Morrissey CDs have all put in timely appearances, but if music were really a vital part of their makeup, they'd do what every male music nut does and drop references to obscure bands and labels, trying to one-up rival anoraks. All right, maybe that's fanciful. But you have to appreciate Koizumi's dedication in the face of ridicule.