Thousands of subway passengers in major cities worldwide kicked off their pants on Sunday as they celebrated the annual day No Pants Subway Ride day.
Today marks the 15th annual No Pants Subway Ride since performance art group Improv Everywhere started the event in New York City in 2002.
Men and women of all ages - but mainly adults - were seen standing on subway platforms and sitting in seats showing all colors of underwear and bare legs. Even some toddlers hung in their parents' arms without pants on. The chilly temperatures in northerly cities such as New York or Helsinki were no deterrent for pants-less commuters.
The event has since spread to more than 40 cities in 20 countries - mostly in Europe and North America - with a few participating in Asia including Hong Kong and Tokyo.
In London, tube commuters performed gymnastics-like maneuvers while hanging bare-legged from the handrails.
In Prague, young people without pants practiced body contortions alone and with their friends on the subway platforms.
And in Hamburg, participants all removed their pants at once on the subway platform.
The pants-less day took place in Japan's capital early on Sunday afternoon in the bustling Tokyo train station, according to the Facebook events page of No Pants Subway Ride Tokyo 2016.
The details on the page instructed participants to remove their pants and put them in their backpacks "as soon as the doors shut at the stop before yours."
"If anyone asks you why you've removed your pants, tell them that they were 'getting uncomfortable' (or something along those lines). Insist that it is a coincidence that others also forgot their pants. Be nice and friendly and normal," the page stated.
As photos from around the world show, the day is not aimed at exhibitionism, nor do very many bare-legged riders wear lurid underwear.
Indeed, one of the few rules on the Tokyo event page reads, "Don't wear a thong or anything else that might offend people. Our aim is to make people laugh, not piss them off."
More than 4,000 New York City commuters took off their pants while riding trains on Sunday, then met at Union Square later on for an afterparty, according to Improv Everywhere's website.