TOKYO and GIFU, Japan — The mileage my sneakers earned on my first full day in Tokyo was 12.4 miles, and impressively, some of my gum wrappers logged just as much.

As one of the world's largest cities, Tokyo requires travelers to be out for hours at a time, and I carried each day's garbage with me until I returned to my hotel at night.

Back at my hotel every night, I'd flip my tote bag upside down, and out came a flurry of konbini snacks, souvenirs, omamori (good luck charms from temples), along with empty gum wrappers, random receipts, crumpled tissues and perhaps an empty water bottle. This wasn't by choice; there are so few public trash cans in Japan.

Over my four days in Tokyo, I never saw one trash can out on the street. I only found them in konbini (convenience stores), a few train stations and Yoyogi Park, a popular green space in the city center.

I soon left the city for the countryside, slow traveling through the Gifu Prefecture. At the Takayama morning market, where travelers can sample local delicacies such as beef nigiri sushi, I ran into the same issue. Looking to discard my wrapper and fork after finishing a baked sweet potato, I approached a bin before being stopped by a bright-red sign warning that it was for mail parcels and absolutely not for garbage. Apparently, I wasn’t the only tourist to make this mistake.