What better test for false dawns than the Land of the Rising Sun?

They hope, but, more importantly, they are beginning to believe.

The mood music in England's camp this week has been upbeat - a stark change to the tournament build-up.

On Friday, coach Steve Borthwick was asked about his own happier demeanour.

"I think I smile a lot," Borthwick replied with one of his lesser-spotted grins.

"Don't you agree?" he asked Courtney Lawes, who duly, if a little uncertainly, concurred to more laughter.

Earlier in the week, full-back Freddie Steward cheerfully talked journalists though an eagle two - massive drive, eight-iron approach, nerveless putt - he had scored in a golfing victory over Ben Earl and Joe Marchant.

The favourites for the team's padel tournament - Alex Mitchell is 'very good', but Max Malins is 'phenomenal' - were revealed, while Jamie George picked the best XI if England's rugby players were to swap the oval ball for cricket's lacquered cherry.

Second row Ollie Chessum - a 'big, red fiery goose' - leads the bowling attack apparently.

All fun and games amid the serious training. But it comes from surer foundations.

After a bloody-minded, blooded-brow win over Argentina in Marseille, England are on the up on the pitch.

George Ford, who potted three dead-eyed drop-goals in a 27-10 success, made light of the suspended Owen Farrell's absence. Earl, all wrecking ball power and pinball energy, did the same for the banned Billy Vunipola. Maro Itoje came to the party. Manu Tuilagi flew into tackles. Mitchell injected a shot of urgency and tempo into a flat-lining backline.

There was even a suggestion that sluggish warm-up performances had been part of the plan all along, that England's fitness staff had deliberately overloaded the players to ensure they peak when it matters.

This spring in England's step must be followed by a step up in Nice though. Resting on laurels is not an option when they face the Brave Blossoms.

Because the win over the Pumas - for all its raging defiance - was lacking in other areas.

1. Discipline: England coughed up only seven penalties, but the damage had been done in the first three minutes. Tom Curry's head-on-head collision with Juan Cruz Mallia - more puppyish enthusiasm than bully-boy aggression - put England a man down.

It is a position England are getting used to. This year they have collected more cards than a croupier. In their past six matches, they have been shown four reds and four yellows.

England fought and thought their way out of that particular corner, but better sides than Argentina will box them in and knock them out.

Ireland enjoyed a similar advantage against England in March 2022 following Charlie Ewels' early red card, ultimately made the maths pay and surely would again.

2. Attack: England have been toothless, rarely creating clear opportunities and often hashing them when they do. Against Argentina, Jonny May was left exasperated as team-mates drifted with the ball, swallowing up his space and a route to the line.

England have averaged fewer than two tries a game this year, well down on par for a top Test team. Borthwick says other, underlying numbers are more positive and progressive.

He also points out that in England's two best World Cup campaigns - 2003's victory and 2007's run to the final - the team scored only four tries in eight matches against top-level opposition.

At the modern game's exchange rate though, that sort of output doesn't tend to bring in the big prizes.

3. Accuracy: Have England got the awareness to sense Japan's vulnerabilities and then the ability to exploit them? They certainly plotted an impressive escape route against Argentina, but while the best sides play 4D chess, England often look like toiling draughts men.

England recognise all of the above.

Borthwick has stressed the importance of keeping 15 players on the pitch.

Elliot Daly promised the tries were coming.

"We are investing more time than normal into our attack, we think we are improving but we have to show it at the weekend," admitted wing Jonny May.

Japan will come with a plan. Borthwick was part of their coaching staff at the 2015 Rugby World Cup when a Bok-busting plot, months in the making, came to fruition.

That day in Brighton, their hits were low, their energy was high and South Africa, try as they might, couldn't pin down Japan's quicksilver handling game.

Japan built on that upset four years later, beating Scotland and Ireland to make the World Cup's last eight for the first time.

Their development has slowed since. Without the bubbled protection of the Six Nations or Rugby Championship, their fixture list was wiped out by the coronavirus pandemic. The Sunwolves no longer are part of Super Rugby, denying Japan's young prospects a proving ground.

A 42-21 loss to Italy in Japan's final warm-up match was more telling than an opening-round 42-12 win over Chile, the tournament's lowest-ranked side.

England should beat Japan. They have in all three of their previous Test meetings by a margin of more than 20 points. Victory would be well-earned, but it wouldn't be enough. A team that has had so little to shout about needs a statement.

Nice, a town of private jets and public displays of excess, is used to Englishmen promising much. Four years ago, billionaire Sir Jim Ratcliffe bought the local football club with plans to challenge Paris St-Germain's dominance.

So far, so little. Since Ratcliffe's investment, they have meandered around mid-table, failing to trouble the elite.

But on Friday, Nice went to the Parc des Princes, beat PSG and climbed above them to second in Ligue 1.

Maybe it is the start of something. Perhaps, for England, Sunday could be too.