Sure, it helps hugely when the players also display a ferocious overall commitment to the cause, as the Japanese did on attack and defense in the shocking upset of Ireland in their last game in Shizuoka to leave them with two wins from two in Pool A.
But Japan's growing success at the Rugby World Cup appears to be built on many small blocks.
Like coach Jamie Joseph identifying that Japan's humidity this time of year and the resultant extra-slippery ball will make it tough for most other teams to pass and catch. So, Japan has thrown lots and lots of passes, trusting its familiarity with the conditions to give it the edge and never giving a bigger, stronger team like Ireland a moment's peace.
There are other things: Defense coach Scott Hansen, like Joseph a New Zealander, drilling the team to get two men to make every tackle. That'll give the smaller Japanese players a better chance of stopping the opposition but also help them swarm the breakdown. That led, Hansen said, to a 93% tackle efficiency against Ireland.
That kind of efficiency makes all of Japan smile.
Also, Japan is zeroing in on the absolute minutiae of scrumming technique to help with their relative lack of bulk. Again, Japan did that against Ireland and when the little things worked, it gave the team a major boost.
Ireland had a strong scrum, "but we managed to push them back once and that really gave us confidence," Japan prop Jiwon Koo said.
Joseph was a squashed-nosed New Zealand hardman in his playing days. He still is. But he has belied that reputation with his precise approach with Japan and his team have maybe tapped into the Japanese culture, where the delight appears to be in the detail.
"We have the preparation scheme and it doesn't matter what opposition we face," said flanker Pieter Labuschagne, who stood in for Michael Leitch as Japan's captain against Ireland and retains the role for Samoa despite Leitch's return to the lineup.
And so, to Samoa at City of Toyota Stadium on Saturday. A team which might be the antithesis of Japan when it comes to rugby, the Samoans are big, big men with a tendency to play on instinct over anything else.
While Japan is finely tuned, Samoa appears a little ragged. Two players yellow-carded within two minutes of each other for dangerous tackles in the opening game, then banned for the rest of the group stage afterward. Winger Ed Fidow warned for punching in that opening win against Russia, and then sent off after two yellow cards in the second game against Scotland.
Then there's the result against Scotland: A 34-0 drubbing, the first time Samoa had failed to score a point in a Rugby World Cup match.
In the context of Japan, Samoa may appear like a broken machine. But that's not a fair comparison.
While Japan has the budget to put such a detailed plan in place, and constant access to their players, Samoa's players are spread all over the world at clubs in Britain, France, Australia, New Zealand. They get little time together and the coaches have comparatively little money to prepare.
They are a different story altogether, but still dangerous to Japan's carefully calculated plan if they're on-form.
They'll also have Samoan Prime Minister Tuilaepa Sailele Malielegaoi supporting them in Toyota. He's in Japan on an official visit, and also visited with the team.
"He's right behind us, just like the rest of the country, and told us to get out there and enjoy ourselves," Samoa coach Steve Jackson said. "It was probably just the lift that the players needed because they were pretty down after our last game."
Not that the Japan players can't enjoy themselves too. They sure are right now.
The team, brilliantly drilled, is also electrifying when it plays to the game-plan. The 19-12 victory over Ireland, after being 12-3 down against one of the world's top teams, threw nearly 50,000 people at Shizuoka Stadium, and much of a country still getting to grips with rugby, into ecstasy.
The final piece of Japan's preparation for that Ireland game was captain Labuschagne putting on a movie, "The Pursuit of Happyness" with Will Smith, for the players to watch the night before. Yes, Labuschagne planned it in advance. Labuschagne is South Africa-born but he's been in Japan long enough to adjust.
And it's important to note the word "Happyness" is intentionally misspelled in the movie title. It's an integral part of an inspiring plot. The delight of the movie is in the detail, you see.
- AP
Match details: Saturday 5 October, 11:30pm, City of Toyota Stadium, Toyota City.
Referee: Jaco Peyper (South Africa)
Squads
Japan
15. Ryohei Yamanaka, 14. Kotaro Matsushima, 13. Timothy Lafaele, 12. Ryoto Nakamura, 11. Lomano Lava Lemeki, 10. Yu Tamura, 9. Yutaka Nagare, 8. Kazuki Himeno, 7. Pieter Labuschagne (c), 6. Michael Leitch, 5. James Moore, 4. Wimpie van der Walt, 3. Jiwon Koo, 2. Atsushi Sakate, 1. Keita Inagaki
Reserves:
16. Shota Horie, 17. Isileli Nakajima, 18. Asaeli Ai Valu, 19. Uwe Helu, 20. Hendrik Tui, 21. Fumiaki Tanaka, 22. Rikiya Matsuda, 23. Kenki Fukuoka
Samoa
15. Tim Nanai-Williams, 14. Ah See Tuala, 13. Alapati Leiua, 12. Henry Taefu, 11. Ed Fidow, 10. Ulupano Seuteni, 9. Dwayne Polataivao, 8. Jack Lam (c), 7. TJ Ioane, 6. Chris Vui, 5. Kane Le'aupepe, 4. Piula Faasalel, 3. Michael Alaalatoa, 2. Seilala Lam, 1. Jordan Lay.
Reserves:
16. Ray Niuia, 17. Paul Alo-Emile, 18. James Lay, 19. Senio Toleafoa, 20. Josh Tyrell, 21. Pele Cowley, 22. Tusi Pisi, 23. Kieron Fonotia
How to watch:
The Herald will have live updates of the match from 11:15pm. Spark Sport coverage starts at 11:00pm. Kickoff is at 11:30pm.
Head-to-head:
Japan and Samoa have played 15 times, with Samoa winning 11 and Japan claiming four.
Last match: Japan won 26-5 at the RWC in 2015.
Prediction: Japan by 17.
Group standings
