The Pacific Nations Cup champions were protected by the standard tournament secrecy measures. A giant banner around the club's perimeter shut out prying eyes, standing on tiptoe beat the screens.
A couple of policemen wandered about, presumably to ensure no one viewed Japan's hit out against a near full-strength North Harbour ITM Cup side disguised in Silverdale jerseys.
"If they work as an eight together I think they can match France," said Harbour hooker James Parsons after a mini scrum session.
"We scrummed physically against them although with the field play it wasn't full on and at the breakdowns there was a gentleman's agreement."
The Japanese press were in full battle mode, with one member telling Japanese prop Naoki Kawamata the pack had scrummed too high against Italy.
Kawamata took it in his stride and said he wasn't nervous about facing France.
"I'm more nervous about taking my kindergarten exams," said the 118kg forward, who wants to be a pre-school teacher.
Seven players then headed to Red Beach School where they received a boisterous reception from the pupils who have adopted the Japanese team.
Letters from the children were pinned to the wall at their pre-World Cup camp and at their North Harbour World Cup base.
The unofficial liaison officer was Andrew Turner, former Blues trainer, who has three daughters at the school. Turner was a trainer at the Yamaha and Toyota clubs and knew the Japanese officials.
Japan's giant Samoan centre Alisi Tupuailai wowed the children by claiming to be 17. Then the kids immediately got the joke when tiny halfback Fumiaki Tanaka announced his position as lock. Maybe his sparkling eyes and smile gave him away.
The children weren't the only ones who adopted Japan.
Former Otago players Shaun Webb and Ryan Nicholas, as well as Tongan Sione Vatuvei, have just obtained Japanese citizenship.
The squad includes New Zealanders Justin Ives, Luke Thompson, James Arlidge, Murray Williams and Michael Leitch, who went to Japan as a 15-year-old on a rugby exchange.
Ten squad members were born outside Japan.
"I've lived in Japan six and a half years and spend almost all of my time there. If I came back this might be home again but Japan feels like home now," said Webb.
The 29-year-old, with 31 caps, said the Japanese mission was clear.
"We are here to win at least two games and we've got a pretty good record against Tonga and Canada. France and New Zealand? We'll give it a really good dig."