Kirwan, a part of the original New Zealand World Cup-winning squad in 1987 and 63 times an All Black, will now take his team into a tough-looking World Cup group that includes Australia, Fiji, wales and Canada in France this September.

He already has knowledge of his new charges, as a result of a spell as a technical advisor to the team during its qualifying matches in Hong Kong in November.

"We are determined to do our best to win all the matches in the World Cup," said Kirwan to reporters.

Kirwan takes over from Jean-Pierre Elissalde, who was sacked after taking up a post with Bayonne concurrent to his role as coach of Japan, without consulting the JRU.

As well as Kirwan's coaching experience in Japan, he also played in Japan's top League for NEC during his last three active playing seasons.

He was a staunch supporter of Japan's bid to host the Rugby World Cup in 2011, ruffling many feathers back in New Zealand.

He now  plans to choose 60 elite Japanese players, which will be whittled down to the final World Cup squad during the Pacific Nations Cup in June.