In the days before the match, the Japanese waxed lyrical over the contribution of Germany and its coaches for helping to develop the game in the country in the decades after World War Two.
But when they left the pitch at Doha's Khalifa stadium as sensational winners they had clearly outsmarted their teachers.
Strikes from Freiburg's Ritsu Doan (24) and VfL Bochum's Takuma Asano (28), who struck from fellow Bundesliga player Ko Itakura's (25) deep free kick, gave the Asians their first-ever win over Germany.
It was the two scorers, both substitutes, who woke their team up from their first-half slumber.
In true German tournament fashion, Japan refused to surrender even after a one-sided first half in which Germany had 16 efforts on goal and possession of over 70%. Japan won the game with just 26% possession.
The introduction of Doan, nicknamed 'the Japanese Messi' and Asano in the second half lit up their game as they hustled and turned the tables on their opponents with high pressing and relentless work while charging forward.
A total of eight Japanese players in the squad compete in Germany's top two divisions and they brought back the right lessons learned there.
Their win, a result of pure determination and grit, had them punish their opponents for their lackadaisical approach to the game.
Even though he was a 57th-minute substitute, scorer Asano had the ball in the opponents' box more times than all but two German players.
Germany will be asking themselves how they lost a game which should have been killed off in the first half but they ultimately paid a dear price for their careless play and below-par finish.
They used to punish opponents with their never-say-die attitude for decades but on Wednesday they were on the receiving end of late goals.
Japan continued to hope and after goalkeeper Shuichi Gonda (33) made a quadruple save to keep them alive, they delivered the double punch for yet another upset in this tournament.
The Germans huffed and puffed but could not find a second goal, with highly rated players like Jamal Musiala and Kai Havertz showing only brief glimpses of their skills and their known weakness in defence once more blatantly obvious, especially in the winner.
In the end, the Japanese proved as determined as their own fans who did not stop singing for over 90 minutes. The German fans were nowhere to be seen or heard.
Moriyasu praises his side's comeback
Japan coach Hajime Moriyasu (54) said not too long ago his team might have lost Wednesday's opener against Germany at the death, rather than claiming a stunning victory over the four-times world champions.
With stoppage time, they had to hold out for 15 minutes after taking the lead, bringing back memories of their loss in the last 16 of the last World Cup when they gave up a 2-0 lead against Belgium and lost to a stoppage-time goal.
"At the end, they came at us with the full power, in the past maybe we would have lost but the players have been playing in Germany and Europe they've learned so much from that, so we held on," Moriyasu told reporters.
"United as one, we needed to hang tough until the final whistle went and we were able to grasp our opportunity."
Moriyasu said the "historic" victory was the result of meticulous planning and the flexibility of his players when they were faced with the full might of the Germans in a one-sided first half and went a goal down.
"We wanted to start aggressively, we wanted to dominate the game but Germany are very strong so we needed to defend persistently and take our chances," he said.
"In our tactics, we had many options and looked at many scenarios. We knew there was a chance we could go a goal down, we planned for it, we prepared for it."
Moriyasu brought on five substitutes in the second half with two of them, Doan and Asano, providing the goals that secured the unlikely victory.
"It was very difficult we were struggling a lot," said goalkeeper Gonda.
"But this is a World Cup, everyone wants to play. The subs came on and re-energised the team. Maybe one player is not that strong but together we were able to do it."
Progressing to the next round will still be a tough task from a Group E also featuring 2010 champions Spain and Japan's next opponents Costa Rica.
"We want to go to the quarter-finals, this is the first step," Gonda added.
"Japan has its own character and the way we do it is as a team. Doan and Asano scored but we did it together."
