By Jonathan Beale
BBC News, Washington
This is Prime Minister Koizumi's North American "farewell tour" - he is stepping down from office in September.
He has already visited Ottawa, before the obligatory stop at the Carnegie Hall of politics, the White House.
The two leaders have formed a "special relationship"
But most of the media attention will be on his final venue, a visit with President Bush to Graceland - the home of Elvis Presley.
It was all apparently the president's idea, but still, the King's taste in fittings and furnishings - like shag pile carpet on the ceiling - makes it a very strange setting for two world leaders.
But hey, Mr Koizumi is a big fan of Elvis - and Mr Bush is a bit more rock-n-roll than some of his more conservative aides.
This is President Bush's way of thanking a close friend who has stuck with him through thick and thin.
And it will certainly provide more colour than even the White House Rose Garden in full bloom.
The tour guides for this visit: Priscilla and Lisa Marie Presley - Elvis's former wife and only child.
Prime Minister Koizumi not only sports a Presley-esque haircut, he shares a birthday with the King and loves his music.
In 2002 he compiled a charity CD called Junichiro Koizumi Presents My Favourite Elvis Songs.
The two men share the same birthday
He has even serenaded the US president with a rendition of I Want You, I Need You, I Love You.
That in fact has been the background track to this relationship, rather than Heartbreak Hotel or You Ain't Nothing But A Hound Dog.
US-Japanese relations have never been better.
Mr Koizumi and Mr Bush have forged a strong personal bond that has shaped their two countries' policies.
While Mr Koizumi likes to quote Elvis to set out his strategic position, George W Bush prefers to refer to history to show how international relations can change for the better.
His father - the first President Bush - was a pilot in the Pacific in the Second World War, fighting Japanese aggression.
Japan of course has played its part in transforming the relationship.
Mr Koizumi committed Japanese troops to Iraq - no small commitment given his country's history.
Michael Green, until recently a senior advisor to the president at the White House, says that Japan has become " the UK of Asia" - forming another "special relationship" with the US.
Proof: Japan is the only country so far that the US has said it would support for membership of an expanded UN Security Council.
The serious stuff
Before the fun of Graceland, Mr Bush and Mr Koizumi will have to address the more serious issues of North Korea and Iran's nuclear ambitions.
Both Washington and Tokyo have been alarmed by Pyongyang's preparations to test launch a long-range ballistic missile and have been urging their neighbours to step up the pressure.
Japan and America are working in concert to try to persuade North Korea to restart the six-party talks on Pyongyang's nuclear programme.
Tokyo has also said that it is prepared to freeze Iranian bank accounts if Tehran refuses to suspend uranium enrichment.
All the more reason for the president to have a tear in his eye when he bids farewell to Junichiro Koizumi.
Italy's Prime Minister Silvio Berlusconi has gone. Tony Blair is leaving soon
Perhaps the Japanese prime minister's final Elvis rendition for the President should be Are You Lonesome Tonight?