The routine of cleaning up stadium stands by Japanese supporters that became the standard at the World Cup in Russia is spreading to soccer fans of other countries.
While most people in Japan are well-acquainted with cleaning rituals from their schooldays, the practice of tidying up stadiums from a worldwide perspective is extremely unusual.
Now not only has cleaning -- including the Samurai Blue's immaculate treatment of the bench and dressing room at stadiums in Russia -- become a hot topic of the World Cup but it has gone beyond the scope of sports as a way of spreading "Japanese cleaning culture."
"It has been 10 years since I started to attend international football matches as a spectator, but this is the first time I have cleaned with supporters of opposing teams," said Hirokazu Tsunoda, a well-known Japanese supporter from Chiba Prefecture, east of Tokyo, who notably wears a "chonmage" traditional topknot wig as part of his outfit.
After Japan's first match in the group stage of the World Cup, a Colombian supporter unexpectedly asked Tsunoda for trash bags, and then proceeded to help the Japanese group of supporters with the cleanup effort in the stands at Mordovia Arena in Saransk.
"I was surprised because I assumed that he just wanted trash bags as a souvenir," the 55-year-old Tsunoda said.
According to Tsunoda, the stadium cleanup activities date back to when Japan debuted at the World Cup in France in 1998.
In the beginning, Japanese supporters brought blue trash bags with them because blue is the national team's color and they would use them to turn the stands blue. Gradually, however, supporters began to use them not only to cheer on the team but as the actual trash bags they were meant to be.
Participants in the cleanups have increased over the years.
In Japan, cleaning is almost revered as a spiritual practice from the time children are young. Students, in fact, develop a custom of cleaning their schools from an early age. This is in stark contrast with many Western countries where generally cleaning is left to sanitation workers, experts say.
"In Japan where cleaning is closely linked to education, it is prized as good conduct," said Midori Otake, an honorary professor at Tokyo Gakugei University who specializes in home economics.
The response to the supporters' cleanups has been big on social media, and their conduct has given the Japanese team a reason to be proud as well. Japanese players have even been questioned by foreign media about the custom of leaving areas spick-and-span.
"In Japan, we have a saying that you leave a place cleaner than when you came," Japan defender Maya Yoshida said when answering a question about Japanese supporters cleaning stadiums at a press conference during the tournament.
In recent years, picking up garbage has caught on in cities and towns overseas.
Green bird, a nonprofit organization established in Tokyo's Harajuku district in 2002 whose volunteers are dedicated to keeping streets clean, says in the past several years it has received an increasing number of inquiries from overseas about how to conduct cleanups.
Members of the NPO who have relocated abroad have expanded their cleaning activities to various cities, including Dakar, Helsinki, Paris and Shanghai. Initially, they would often receive bizarre looks from people wondering why they go out of their way to pick up litter. Slowly, their continued efforts have borne fruit.
In Paris, the number of participants grew suddenly after the local media drew public attention by reporting on the trend.
"Our goal is not to simply cleanup, but rather to raise public awareness about littering and the environment through cleanup," said green bird representative Toshinari Yokoo, 37.
"I'm confident that picking up garbage will firmly take root overseas as well as cool Japanese culture."