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 tomorrow'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 ten 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 Korea Republic.
"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.