Supporters of the Japanese national football team were seen cleaning up Qatar's Khalifa International Stadium after their win against Germany. They were also seen cleaning up rubbish after the opening match between Qatar and Ecuador.
But why do fans of the Blue Samurai do something the football world first took notice of at the 2018 World Cup in Russia?
![](https://i.ytimg.com/vi/0FWzaFy4EJs/maxresdefault.jpg)