Everyone’s always warning tourists to Japan to mind their manners when they’re here. That’s why I find it fascinating when people in Japan themselves don’t agree on what constitutes good manners. A recent social media post has started a debate over the proper use of smartphones on trains – particularly when you’re near a priority seat.
The X post on March 3rd from lawyer and celebrity talk show guest Yamaguchi Mayu relates an experience she had on a train ride:
“I was standing by the door on an uncrowded train checking my email when a guy across from me sitting in a priority seat said, ‘Turn your phone off or stand over there, please.’ When I stared blankly, he asked, ‘Do you speak Japanese?’ I apologized and did as he said. I know you’re supposed to turn your phone off near priority seats on crowded trains, but does that mean I can’t check my mail where no one’s even sitting?”

Yamaguchi’s tweet refers to a rule on Japanese trains meant to protect people with pacemakers. It’s rooted in a fear that a cell phone’s signal could potentially disrupt the lifesaving equipment.
You’ll see signs to this effect near priority seats in every train car in Japan. Some will specify that you only need to do this when the train is crowded. Others will ask you to do it regardless of the train’s status.
A belief not based in reality

This caution, however, has no basis in scientific fact.
Want more news and views from Japan? Donate $5/month ($60 one-time donation) to the Unseen Japan Journalism Fund to join Unseen Japan Insider. You'll get our Insider newsletter with more news and deep dives, a chance to get your burning Japan questions answered, and a voice in our future editorial direction.
According to the American Heart Association, cell phones “are a very small risk to ICDs and even less of a risk for pacemakers.” While there might be a tiny risk, it only seems applicable if your phone is very near the device – e.g., in the pocket of your shirt.
The post sparked a discussion on social media site X as well as a fevered discussion on Yahoo! News Japan. Most commenters reiterated that modern smartphones are of no risk to pacemakers several feet away. Some labeled the belief an urban legend.
The debate echoes similar recent debates around how you should hold your backpack on trains. That one’s still being debated. In previous years, Japanese passengers have gone off on things that tick them off on trains and in train stations, with improper cell phone use coming in at number four. Placement of bags came number three (and would probably rank higher now, given the preponderance of tourists’ luggage.)
Still, even if there’s no real risk of using smartphones near priority, this post shows that many people still believe there is. If you want to avoid a spat on public transit in Japan, it’s probably best to keep your phone in your pocket if you’re anywhere near priority seating.
Get More UJ
What to read next

Before Mario, Nintendo sold hanafuda cards to the yakuza. Read the 400-year forbidden history of the flower cards that tricked the Shogun.

The company took pains to reassure its Japanese customer base that information about their masturbatory habits was safe.

Japan gets less sleep than any other nation. But the country’s workaholic Prime Minister doesn’t seem to care.