Jet-setter: Nakamura could do with a public holiday himself [GALLO/GETTY]

Okada refused to release the trio from training on Monday for the traditional ceremony for those who have reached 20 – the mark of adulthood in Japan and a day observed with a national holiday.

'No need'

"There's no need for them to go to a coming of age ceremony," Okada said.

"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."

Yemen opener

Japan open their Asian Cup qualifying campaign with a home game against Yemen on January 20 before playing Bahrain away eight days later.

They then play Finland in a friendly on February 4 before taking on Australia
at home in a 2010 World Cup qualifier on February 11.

Midfielder Shunsuke Nakamura will break the pain barrier to play against Australia, he announced on Monday.

The 30-year-old played in Celtic's 2-1 Scottish Cup victory over Dundee at the weekend despite suffering from a groin strain.

No rest for Naka

"Celtic are fighting for the title so I can't rest," Nakamura said.

"It's not too painful."

Nakamura has struggled with the frequent long-haul trips to play in Japan's World Cup qualifiers and is expected to join the national side late.

"It would be better to have a week in Japan to prepare but there's nothing I can do about it," he said.

"It's exhausting to think about all the games (for Celtic) coming up before
that."

"I'm only human – it's tough."