In Japan, pet fish playing Nintendo Switch run up bill on owner's credit card

(Jeffry Surianto)

Here's something you don't see everyday. Pet fish playing a video game in Japan managed to log on to the Nintendo Switch store, change their owner's avatar, set up a Pay Pal account and rack up a credit card bill.

And it was all seemingly livestreamed, in real time, on the internet.

The fish in question belong to a YouTuber known as Mutekimaru, whose channel is popular with the gaming community for its videos featuring groups of tetra fish that "play" video games.

Mutekimaru had previously installed sophisticated motion detection tracking software in fish tanks, enabling the fish to remotely control a Nintendo Switch console.

But the technology, and the fishes' apparent mastery of it, led to an unexpected turn of events earlier this month while Mutekimaru was live-streaming a game of Pokémon.

Mutekimaru had stepped away for a break when the game crashed due to a system error and the console returned to the home screen.

But the fish carried on swimming, like fish tend to do, and seemingly continued to control the console remotely from their tank.

During the next seven hours, the fish reportedly managed to change the name of their owner's Switch account before twice logging into the Nintendo store, where users can purchase games and other downloadable content.

They also managed to "check" legal terms and conditions, downloaded a new avatar and even set up a PayPal account from the Switch -- sending an email out to their owner in the process, video from the livestream appeared to show.

But things didn't end there. The fish were also seen adding 500 yen ($4) to Mutekimaru's Switch account from his credit card during the livestream -- exposing his credit card details in the process, the YouTuber revealed in a follow-up video about the episode.

By this point, thousands of comments were streaming in as viewers watched the unintended takeover being livestreamed on the channel, and the incident went viral on Twitter, where thousands of Japanese users shared their amusement.

Mutekimaru later said that he had contacted Nintendo to explain what happened and asked for a refund of his 500 yen.

Nintendo declined to comment to CNN, citing customer confidentiality.