By Alastair Leithead
BBC News, Tokyo
The small, white van flies around the narrow country roads with its four huge tannoys blaring out the electioneering message "Vote Kazumi."
Suddenly it screeches to a halt, the door flies open and Kazumi Ota leaps out, running to meet a voter to shake hands and bow vigorously before racing off to greet the next potential supporter.
Kazumi Ota, Japan's youngest female MP, epitomises energy and vitality
Her assistants, in matching Kazumi colours, desperately try to keep up with her pace and energy, but are left to dish out the leaflets and get back to the car before the whole convoy tears off to surprise another sleepy village in rural Japan.
Ms Ota is 29 years old and was the youngest member of parliament when she won her seat four years ago.
She sums up the message the opposition Democratic Party of Japan (DPJ) wants to get out - it is all about being young and energetic.
It is about change in a place where MPs used to be old and stuffy - certainly not women - and even passed their job from father to son.
"Japanese people, by nature, don't like change and are conservative," said Ms Ota.
"The country used to be well off but now there is inequality and a gap between rich and poor is taking hold. That's why they want change."
The Liberal Democratic Party (LDP) has been almost continually in power for five decades, but the polls say the opposition will win a landslide victory on Sunday.
In Japan, the politicians and the bureaucrats who have wielded the real power have developed a cosy self-serving relationship. There is even a word for it: "shigarami".
"I'm young, I'm a woman and I don't have shigarami ties," said Ms Ota.
"In Japanese politics the old generations have not handed over to the young generation and that should happen now."
Ms Ota's own story tells how Japanese society has already been changing and politics is only now catching up: she used to be a hostess girl - a job once seen as seedy and underground but now accepted.
"Night-work used to be looked down on as just for drop-outs, but now it's more accepted and accessible," said Manami Moriyama, 35, herself a former hostess who now writes books glamorising her old job.
"Students can do it part-time, you can earn good money when there are so few other jobs around. It's exciting and glamorous."
Japan was once the bastion of the so-called "salary-men" - hard workers who had jobs for life in a conservative society where individualism was scorned.
Now, you only have to wander the streets of Tokyo to see how that pent-up repression has boiled over into the wackier side of Japanese pop culture where the geek is king.
Cos-play is popular - dressing up as a favourite animation cartoon, or anime, character.
Many enjoy adopting the character - and costume - of anime personalities
Bo Peep-meets-French-maid is a current teenage favourite, but it is not just the young - big-eyed anime models wear school uniforms with short skirts and tight tops.
Danny Choo is the 30-something son of the famous luxury shoemaker Jimmy Choo, and he runs an internet business from Tokyo which appeals to anime geeks the world over. He says it gets 20 million hits a month.
His cos-play is a Star Wars Stormtrooper and he happily puts it on for a stroll around town.
"When I watch anime I feel like I am in a completely different world," he said.
"I guess it's something you have which takes you away - I wouldn't call it escapism, but it lets you indulge another world."
It's the side of Japan which has been breaking free from the customs and traditions of old.
Time for change?
Salary-men used to be happy with the security their lives had, but with jobs no longer for life and unemployment at the highest level ever things are changing.
For two decades it has been hard but this recession was the tipping point - by next year China's economy will have overtaken Japan, and almost a third of all people will be pensioners. That is where the call for change comes from.
Tokyo remains a mix of tradition and technology
Masaru Sato is 65 years old and does not blame the state for his circumstances after losing his job 10 years ago.
With the job came a house but with unemployment comes a neatly kept blue tarpaulin tent in a Tokyo park.
He makes a little money recycling and has signed off from society. He may have lost his right to vote, but doesn't mind.
"It won't make much difference whoever wins the election, but we should give the opposition a chance," he said.
"I am looking forward to what new things the DPJ can do. The ruling LDP will probably split - it's just a club for the privileged - their lives are so different from ours and they just do what the bureaucrats tell them to - is there any other country like that?"
People no longer accept the unacceptable - from the homeless on the streets, up to the unchallenged towers of bureaucracy.
If Japan does vote for change, it will be a momentous shift after decades of hidden dissent - think the British Labour Party's victory in 1997, or the rise of Barack Obama.
Japan has had four LDP prime ministers in the three years it took to select the new US president.
On Sunday it will choose a fifth and politics will be shaken up, but whoever it is, the challenges will be just as big.