TOKYO • Japan's sewerage industry has found a way to clean up its dirty and smelly image: elaborately designed and colourful manhole covers with 12,000 local varieties nationwide - including, of course, a Hello Kitty design.
Appealing to a Japanese love of detail and "kawaii" - which means cute in Japanese - bespoke manhole covers adorn the streets of 1,700 towns, cities and villages across Japan and have spawned a hunt craze among so-called "manholers".
The designs represent an instant guide to a place as they feature its history, folklore or speciality goods: a castle design for an ancient town, a bay bridge for a port and Mount Fuji for a city at the foot of Japan's iconic mountain.
As for the city of Tama in the western sprawl of greater Tokyo, locals are pinning their hopes on a more modern Japanese icon - Hello Kitty - to attract tourists, alongside the town's theme park showcasing the much-loved character from Sanrio.
"We'd be happy if people come and take some time for a stroll in our town while looking for the Hello Kitty manholes," said Mr Mikio Narashima, who heads the city's sewerage system division, after the city installed the first of the 10 designed covers.
Veteran spotter Shoji Morimoto said his passion for covers was fuelled after noticing that the central city of Fukui sported two phoenixes on its manholes.
He later learnt that the imaginary birds were a symbol of the town's rise from a devastating US air raid in 1945 and a deadly earthquake three years later.
"I sometimes do research on why the town has that particular design," said Mr Morimoto, who coined the word "manholer" for like-minded people.
The 48-year-old has already visited all the designed manholes in his local area. "Now I have to travel far," he said. "It's treasure hunting for adults."
Manholers take pictures of the covers they visit, with the more obsessive fans taking rubbings.
For others, the interest lies more in "cover bonsai", plants growing on soil accumulated on and around the covers.
More than 3,000 people attended a "manhole summit" in western Japan last November.
To satisfy collector interest, the private-public GKP network, designed to promote awareness on the importance of sewerage in society, has released 1.4 million cards featuring 293 different covers.
The cards are free, but they can be obtained only through local offices, thus working as a tourist magnet. They are numbered in chronological order and come with the manhole's exact GPS information for the convenience of manholers.
"We believe Japanese manholes are cultural products we can boast to the world," said Mr Hideto Yamada, a GKP planning official.
The eastern city of Maebashi held a highly competitive lottery in October as its offer to sell 10 used manhole covers - 40kg of iron - at 3,000 yen (S$37) each was swamped with more than 190 bids.
The history of decorating manhole covers in Japan dates back 40 years when there was a bid to improve the image of the sewerage system, according to GKP's Mr Yamada.
Cover designs must have the same friction level, no matter which direction humans or cars come from, so that people do not slip on them.
This need for friction resulted in placing extra streaks of clouds, sea waves or tiny stars in the background, giving birth to "condensed designs", Mr Yamada said.
Overall, there are some 15 million manholes in Japan, of which only a fraction have colourful designed covers that have been carefully hand-painted.
A plain cover costs some US$600 (S$796) but a designed one can be double that, depending on the number of colours used and the level of detail used.
The craze has since spread online with abundant information on where to find the best manholes via the hashtag #manhotalk.