ITO: Sinking into the steamy hot springs, the giant rodents of Izu Shaboten Koen flick their ears and close their eyes against the camera clicks of fascinated onlookers, drifting into a hazy midday nap.
They might not know it, but the five capybaras are the star attraction at the zoo some two hours by train south of Tokyo, the host of this year's summer Olympic Games.
Zookeepers are banking on the tourism appeal of the world's largest rodents to cash in on the fortuitous coincidence of Japan hosting the Olympics in the Chinese Zodiac's Year of the Rat.
"The capybaras are the highlight of our zoo, so we're taking the Year of the Rat as an opportunity to push their popularity up even more," said Masahiro Takeda, the deputy zookeeper of Izu Shaboten Koen.
"We're really hoping that this will catch on with people from all over the world visiting Japan too."
Ironically, the capybaras, which are native to the tropical jungles of South America, have been credited with improving the zoo's popularity in the quieter winter months.
The winter tradition of giving the capybaras daily baths started almost 40 years ago, when a zoo attendant cleaning their pen with hot water turned around to find that they were huddled together trying to sit in one of the warm puddles.
In a country with nearly 3,000 hot spring resorts, the baths quickly became a fixture at Izu Shaboten Koen and other zoos across Japan, where the number of capybaras jumped from 126 in 2006 to 422 in 2016.
The rodents have inspired a popular plush toy and associated merchandise called 'Kapibarasan,' and online video clips of bathing capybaras have been viewed hundreds of thousands of times.
At Izu Shaboten Koen, the capybaras, which weigh in at anywhere between 35kg to 65kg, eat apples and leaves dumped by their keeper into their hot bath before drifting off to sleep. When awake, visitors can don special mittens to pet and hand-feed the giant hamster-like animals.
Daytrippers who stop for a bite to eat at the zoo's restaurant can indulge in a capybara-themed beef burger, which features a bun in the shape of the animal, with chocolate eyes and mouth drawn on.
Takeda said he did not have exact data, but estimated the zoo received 20 per cent to 30 per cent more visitors during the winter since the it started showcasing the bathing capybaras.
"I'd only ever seen the capybaras sit in hot springs on TV, so I really wanted to see it in person,” said Kayo Kogai, 23, who was visiting Izu Shaboten Koen on Saturday.
“They look so relaxed … I would really like to join them in their bath,” Kogai’s friend Mizuki Aoki, 23, added with a laugh.