The former Brazil international, 59, led the Blue Samurai from 2002 to 2006 having previously played for and coached Kashima Antlers.
And he said ahead of Tuesday's Group B clash in Saitama: "For me it is very, very nice to be back in Japan and very emotional because I worked here 15 years and have a good impression of the Japanese."
His team will face a tough task, though, with free-scoring Japan the only team to win so far in the group and holding a five-point lead over the competition.
Keisuke Honda's four goals in three games so far make him the top scorer in Asian qualifying, while Ryoichi Maeda and defender Yuzo Kurihara have two apiece as Japan have scored 10 times and conceded only once, in a 1-1 draw with Australia in June.
Iraq were held 1-1 by Oman in their last qualifier and go into arguably their toughest game of the campaign with a makeshift side as Zico counts the cost of their impressive 3-0 friendly win over South Korea.
"Three players got injured in Korea and one player didn't arrive," he said. "I have only got three regulars with me so we will need a complete team effort.
"There are new players that I want to try out and see if they are up to the job but I am confident of getting a result. Mental strength will be the key."
Japan, who beat the United Arab Emirates 1-0 in a friendly last week, will be without Kurihara due to suspension after he was sent off against Australia in their last qualifier.
The same applies to the Socceroos' Mike Milligan as they prepare to face Jordan, leaving the Melbourne Victory man unable to play a role in what defensive colleague Sasa Ognenovski expects will be a tough test for the Australian back line.
Ognenovski, who plays in Qatar for Umm Salal, said: "They've got a great forward structure - that gives most teams headaches.
"When you're playing at home, you're a bit more free, there's a bit more freedom, you really want to take the game on and stuff.
"But when you're over here you know what you've got to do and you've really got to knuckle down and concentrate and make sure everything is done right (defensively)."
Group A leaders Korea Republic will face Uzbekistan without midfielder Koo Ja-Cheol, who scored in their 3-0 win over Lebanon, after he tore ankle ligaments in his last Bundesliga outing for his club Augsburg.
But Bolton winger Lee Chung-yong returns after missing almost the whole 2011-12 season with a broken leg while three of the country's Olympic bronze medal-winning squad - Yun Suk-young, Hwang Seok-ho and Park Jong-woo - are in contention for their senior international debuts.
Lebanon host Iran in Beirut in the other game in the group.
Tuesday's 2014 World Cup Qualifying (AFC) Fixtures
Uzbekistan vs Korea Republic
Lebanon vs Iran
Japan vs Iraq
Jordan vs Australia