The Japanese have only once before reached the knockout stages of the World Cup when, on home soil in 2002, they were eliminated at the second-round stage by Turkey.
But the Blue Samurai are again in the last 16 in South Africa after beating Cameroon and Denmark to finish second in Group E behind Holland.
That set up a showdown with Paraguay at Loftus Versfeld tomorrow and for one of the nations a maiden appearance in the quarter-finals awaits.
Okada is optimistic it will be his side making history, although he knows it will not be easy.
"It will be a challenge for us as we try to get into the last eight for the first time, so we will be doing our absolute utmost to address this challenge," said Okada, whose side were the first team to book their place in South Africa after a relatively comfortable qualifying campaign.
"Paraguay are solid in defence and quick in attack and it's clear they are good team because they finished first in their group, but if we can deliver 100% of what we can do then I'm certain that we will be able to win.
"So tomorrow I hope that physically and mentally we can give everything."
Paraguay helped contribute to one of the biggest surprises of the tournament so far - the early exit of defending champions Italy.
The Italians finished bottom of Group F, with Gerardo Martino's Paraguay going through as winners after beating Slovakia and drawing with the Azzurri and New Zealand.
Okada added of the South Americans: "In their group they were first amongst very good teams. All of them were very good and strong in their group, and they finished first.
"Many their players play in European leagues and they're all good players, and up front particularly they are very quick.
"Perhaps Paraguay aren't one of the most fancied teams but they are strong and good at going from defence to attack quickly, which is something we have to be careful about."
Asked what it would mean back home in Japan if they were to make it through tomorrow's contest, Okada said it would be great news but insists it needs to be viewed as just another step in the right direction rather than the ultimate fulfilment of a goal.
"I would say for the football community it will be wonderful and encouraging news. What the Japanese football community is aiming at, which is to become one of the top teams, will be one step closer if we qualify for the final eight," he said.
"But I have to say if you only pile bricks vertically they will eventually fall down, so we have to support from both sides.
"I personally don't want to base everything on just one result or just one competition. We need to have a longer-term vision, to estimate and evaluate the level of Japanese football.
"We need to be aware of the journey and path which is still ongoing."
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