Millions upon millions of blue or white jerseys have been relegated to the closet. What's a fair-weather fan to do?
Some of them aren't giving up so easily: In the crowds milling outside Osaka's Nagai Stadium, Japan and England jerseys are still the most numerous even though the match is between Senegal and Turkey. Many have painted Senegalese or Turkish flags on their cheeks to indicate their affiliation for the day without surrendering the shirts of the teams closest to their heart.
One group of four Japanese fans in full Senegal regalia confess that they were originally backing England, and that their Senegal kit doesn't indicate that they are pulling for the surviving African representative to win it all. They actually favour Brazil.
"We do see a drop in shirt sales of teams that lose," admits Tatsuhiko Saito, a sales clerk at Ings, one of Osaka's largest sporting goods stores. "Among the teams that are still in it, Brazil is probably the most popular."
The hundreds of thousands of Brazilians living in Japan certainly will be pulling for their homeland, and Brazilian players and coaches have been a staple of the domestic J.League since its inception. But rather surprisingly, perhaps because of the low profile of Brazilian club football in Japan compared with the European leagues, or because the four-time champions have lacked a telegenic icon to draw casual fans, Japanese supporters of Brazil are not as thick on the ground as England's or Italy's.
Still, it's a safe bet that Brazilian canary and blue will overwhelm Turkish red and white in the stands at Saitama Stadium when the two nations meet in the semifinal. Japanese fans don't seem bitter toward the nation that knocked them out of the FIFA World Cup, and some, like Daisuke Matsushima, outfitted with Turkish jersey, floppy hat and flag cape for the match against Senegal, have thrown their lot in with their conquerors.
But even if the sentiment is there, the kit may be missing: stores and street vendors in Osaka are fresh out, having stocked very limited supplies of a team whose group-stage campaign was in Korea and was not expected to go far after moving to Japan for the elimination rounds.
On the other side of the draw, neither the national team nor German clubs have had many Japanese fans historically.
"Fans of Germany tend to be older people who have felt some kind of connection to the country for a long time," reveals Yumi Hiraiwa. "Their uniform doesn't do as well among younger fans." And it is younger fans whose fickle tastes drive the market for replica shirts.
Is Korea's amazing, gutsy rampage, or perhaps the boy-band good looks of their star striker Ahn Jung-Hwan, attracting fans of their long-time Asian rival?
"The Korean shirts are selling better and better," Saito says. "Most Japanese people want to see Korea do well." Maybe, just maybe, if Korea make it through to the final in Yokohama to play their first away game in these finals, they will find a sea of red to welcome them... which would be a fitting tribute to the cooperation that made the first co-hosted FIFA World Cup possible.