By Caroline Gluck BBC correspondent in Seoul

In a trendy shopping area in South Korea's capital Seoul, a predominantly young crowd goes wild as Lee Hoi-chang, the presidential candidate of the conservative opposition party, walks onto a small stage.

You would be forgiven for thinking a pop star had arrived.

I think young people are really excited about this election Chung Ji-eun, 22

The crowd then bursts into a song calling for Mr Lee's victory in Thursday poll, changing the words of what was the unofficial South Korean football anthem during the recent World Cup finals.

Mr Lee, candidate of the Grand National Party, is joined on stage by a student band and bangs a drum, swaying to the music.

A cartoon character pinned up on the stage shows Mr Lee kitted out in hip-hop clothes - although he addresses the crowd wearing a suit and tie.

Key demographic

Aged 67, Mr Lee is having to work hard to show he is not out of touch with younger voters.

They could be key in deciding which candidate is elected, as people in their 20s and 30s make up nearly half of the electorate in a race which has been called a battle between the generations.

Mr Lee - in suit and tie

"In the past, young people didn't vote for the campaigns", explains Shin Eun-kyung, a GNP supporter.

"But in this case, they're very interested in politics - because they're the people who get the burden of this nation, if it fails, but they can be happy if the nation becomes happy," he said.

The turnout rate among young voters in elections has traditionally been lower than for the population as a whole.

Turn-off

Many young people - while politically aware - have been disenchanted by money politics and negative campaigning.

But this time, they feel their vote can make a difference.

"I think young people are really excited about this election", said 22-year-old student, Chung Ji-eun.

"By taking part they hope that politics can change. And young voters are less likely to vote for corrupt candidates," she said.

Another student, Sohn Cho-kwang, is voting for the first time.

"I'm excited to take part in this election. Young people are trying to end regionalism, negative campaigning and old-style politics," he said.

"A new global era is coming. People have new thinking. Young people are tired of seeing South Korea pushed around by countries like the United States", said Hong Su-uoung, 26.

Making voting easier

For the first time in any election, some universities were allowed to install polling booths on campus so that voters who are studying away from home could cast their ballot.

We hope the younger generation's demands for political reform can be heard Activist Park Hong-geun

Groups campaigning to expand the voter base believe it is an important step in encouraging more younger people to vote.

"If only another 10% of young voters actually voted, it could change the final outcome of the election", says Park Hong-geun, of the 20-30 Voters Network, which had campaigned for ballot boxes at universities.

"By having young people more involved in elections it can also change the campaign culture."

Romantic image

Creating more interest in the election is a film which was released two weeks before polling day and is doing well at the box office.

Roh Moo-hyun: Korea's guitar-playing president?

It is a romantic comedy, called the Piano Playing President.

Its director, Cheon Man-bae, is a former student activist now in his 30s.

"I wanted to show what could be a new image of the Korean president," he said.

"Someone who's young, sentimental, loving, and looks after the working class. I think a lot of young voters want this kind of president to be elected for a change. And candidates in this race are also trying to cultivate a new look.

"Recently one of the younger of the two main candidates came to see this film. He told us that if he came to power, he'd like to be someone like the character of the film - and would look after the working class."

That candidate was Roh Moo-hyun, of the governing Millennium Democratic Party.

Regarded as liberal and reformist, he has the backing of many of the younger voters. And he has been playing up his youthful image.

In a recent television advert, he is shown sitting on a stool strumming a guitar and singing a popular student song.

He is hoping to become South Korea's guitar-playing president. But the turnout of young voters will be crucial to that dream.