Okada refused to release the trio from training for the traditional ceremony for those who have reached 20 -- the mark of adulthood in Japan and a day observed with a national holiday.
"There's no need for them to go to a coming of age ceremony," Okada told reporters. "I'm not going either."
Cerezo Osaka midfielder Takashi Inui, his club team mate Shinji Kagawa and Oita Trinita midfielder Mu Kanazaki have all been told they cannot leave Japan's training camp in Kyushu.
Twenty is also the legal age for drinking in Japan, a fact that will not be lost on Okada after several embarrassing drink-related incidents involving Japanese players in recent years.
"Football is more important," said Inui after hearing he would not get the chance to dress up. "I want to get as much as I can out of this camp."
Japan open their Asian Cup qualifying campaign with a home game against Yemen on Jan. 20 before playing Bahrain away eight days later.
They then play Finland on February 4 before taking on Australia at home in a 2010 World Cup qualifier on February 11.
The top two from each of the two five-team groups will qualify automatically from Asia for the 2010 World Cup finals in South Africa.
