One of Japan's main rail operators said Tuesday it is investigating four foreign YouTubers who seemingly took free rides on trains around the country, in the latest case of fame-seeking foreign nationals' antics riling residents.

A YouTuber known as Fidias, who has 2.38 million subscribers, posted a video over the weekend of the four riding trains around Japan without paying for tickets.

At one point Fidias hides in a toilet of a bullet train, pretending to be ill when confronted by a ticket collector, and escapes to board another train where he pulls the same trick.