"I am proud of my players," said Japan's coach, Philippe Troussier. "Of course I didn't expect to get this far."
His Spanish counterpart, Inaki Saez Ruiz, who described the idea of reaching the final as unthinkable a month ago, said the supposed underdogs will be tough opponents. "We met them two years ago but now they are more balanced, they are technically good," he said. "Before, they simply ran around a lot."
The Asians will miss their suspended captain, Shinji Ono, who collected a second yellow card for time-wasting in the 2-1 semi-final win over Uruguay.
Japan have knocked out Portugal, Mexico and Uruguay as well as claiming victories over the United States and England in the first round. They have only three First Division professionals in their team and are missing five top players who were prevented from travelling by the Japanese federation because they did not get hepatitis B vaccinations in time.
Spain began the tournament with a well-deserved 2-0 win over the three- times champions, Brazil.
Nigeria's hopes of hosting the 2006 World Cup have been seriously undermined by the president of football's world governing body, Fifa's Sepp Blatter, who is at the tournament.
"The World Youth Championship has worked but there is a quantum leap between that and the World Cup," said a senior Fifa official, who cited the shortage of hotel beds, poor communications facilities and transport problems in Nigeria.