Japanese World Cup fans cleaned up the stadium after they won. Now others are doing it.

After Japan surprisingly swept Colombia aside at the 2018 FIFA World Cup on Tuesday, the country’s fans did something even more shocking: They swept up after themselves.

You read that right. Japan’s supporters — who traveled all the way to Russia to watch an Asian team beat a South American team for the first time ever at a World Cup — didn’t start partying once Japan clinched its 2-1 victory. Instead, they picked up the mess of wrappers, bags of food, and more they made with garbage bags they’d brought to the stadium specifically for that purpose.

American sports fans, or moviegoers, know that’s not the norm in the US. (This reporter, for example, is definitely guilty of leaving peanut shells under his seat at baseball games. I’m so sorry.)

But cleanliness is the norm in Japan, which is why experts didn’t seem too surprised when I asked them about the fans’ behavior. “Japanese are typically very responsible about keeping public spaces clean and about removing trash,” Sheila Smith, a Japan expert at the Council on Foreign Relations, told me. “But at yesterday’s game, I am sure there was an element of celebration meshed with a sense that as guests, Japanese fans wanted to be sure they honored their hosts as well.”

That doesn’t just happen in happy moments, like after a World Cup win, but even during the worst circumstances.

“A Navy friend of mind described bringing relief supplies into northern Japan by helicopter after 3/11,” says Michael Green, a Japan expert at the Center for Strategic and International Studies, using shorthand for a 2011 earthquake and tsunami that killed around 22,000 people while forcing around 120,000 to evacuate their homes. “In every other disaster, the victims rushed to the helicopter in a mob. But the Japanese stood stoically in line and bowed in appreciation when the helicopter landed with food and water.”

The Japanese government is happy with both the soccer and cleaning news. “We are thrilled with the performance of our national team and the conduct of our passionate fans at the World Cup,” Takehiro Shimada, a spokesperson for the Embassy of Japan, wrote to me in a statement. “Since their childhood, Japanese people learn to ‘cast no dirt into the well that gives you water.’ We truly respect our competition and appreciate the values and spirit of sportsmanship on and off the field.”

That’s pretty evident now. In the video below — recorded by a Colombia fan — supporters of the “Samurai Blue,” as the Japanese men’s team is colloquially known, use their bags to pick up trash.

But the story gets better: Senegal’s fans got on the cleaning bandwagon too. After the West African nation upset Poland 2-1 on Tuesday, its fans also picked up trash around their seating area. It’s unclear if Japan’s example inspired them, or if Senegal’s fans are just similarly considerate and tidy.

Japan and Senegal will look to take out each other — and perhaps some more trash — when they play on Sunday at the World Cup. For what it’s worth, Senegal is heavily favored.