Japan supporters left the stands spotless after their World Cup opener against the Netherlands in Texas on Sunday, saying the practice reflects a deeply rooted cultural habit of tidying up after themselves.

After a 2-2 draw, fans remained in the stadium, carefully collecting litter and placing it in blue plastic bags, leaving the venue as clean as they had found it.

The behavior, learned early in primary school, is driven by a sense of collective responsibility, Japan fan Eita Tanaka told Agence France-Presse (AFP).

“We have to think about everyone,” said the 20-year-old, dressed in Japan’s blue shirt and holding a beer and several cups.

“In Japan, we are taught that when we use a place, we should leave it cleaner than when we arrived. For example, in school classrooms, we tidy up without being told by a teacher.”