A short video depicting the cleaning of Japan's famous bullet trains has become an online hit, garnering more than 2.6 million views on YouTube as of Monday.

As a way to promote Tokyo and omotenashi — Japanese hospitality — to the world ahead of the 2020 Summer Olympics, last fall the metropolitan government invited six foreign journalists to join a six-week Dateline Tokyo program.

They were asked to discover unique aspects of the capital that residents may not be aware of.