For the young women whiling away their evenings with a cappuccino in hand and a cat on their lap, Tokyo's ‘neko cafes’ are the ideal place to unwind and soothe their stresses.

"After a long day at work, I just want to stroke cats and relax," said saleswoman Akiko Harada.

"I love cats, but I can't have one at home because I live in a small apartment. I started coming here because I really missed having fun with cats and touching them."

For Harada and others like her, the ‘neko cafes’ of the Japanese capital are a harmless institution where customers pay a premium for their coffee in exchange for the chance to pet the cats that stroll among them.

But for animal rights activists, these cafes are exploitative places where animals are subjected to unnatural stress.

They welcome a new ordinance, coming into force later this year, that will ban the display of animals after 8:00 pm.

The rules were drawn up by the environment ministry after it received more than 155,000 requests for action from the public - an unusually high number in politically ambivalent Japan.

The law is primarily aimed at the pet shops in Tokyo's entertainment districts that regularly raise the eyebrows of Western visitors with their brightly-lit windows displaying dogs and cats in cramped glass tanks late into the night.

But cat cafe manager Shinji Yoshida says he will also be snared by the law and will have to close in the evenings - his busiest time.

Yoshida's cat cafe in Ikebukuro, a busy commercial and commuter hub in Tokyo, keeps 13 cats in a carpeted room where they have the freedom to jump around and climb all over the large fake tree.

"It is a huge blow to us cat cafes, and it's nothing to do with protecting cats' health," said Yoshida, 32.

"As you see, cats can walk and play freely. I ask customers not to touch them if they are sleeping. At night, we dim the room light," he said. "And cats can rest during daylight."

He says about 80 per cent of his customers are salaried workers who drop in for a welcome change from the daily grind of work and long commutes.

"If I close this cafe at 8:00 pm, I'll see red ink," he said.

Yoshida's customers definitely want the cafe to be allowed to stay open.

Office worker Ayako Kanzaki, 22, began visiting cat cafes three years ago because she loves cats but her apartment is too small to keep one.

"I like to do things at my own pace, and I must say I am not a very social person. So I come here alone, because I want to focus on the cats," she said.

"During the day, cats are mostly sleeping, and if they are awake, they often don't pay attention to the people. In the evening they are very lively, it's more enjoyable."

Saleswoman Harada agrees.

"If cat cafes are shut down at night, I won't have many opportunities to come any more," she said.

Animal welfare campaigner Chizuko Yamaguchi says the sheer number of customers in cat cafes can make life difficult for the animals.

"From morning to night these cats are being stroked by people they do not know. For the animals, that is a real source of stress," she said.

Fusako Nogami, head of animal rights group ALIVE, said the rule change banning the display of animals in the evening was a good thing, but acknowledges the cat cafes are not the target.

Nogami said the commodification of animals in Japan was a real problem, with many people looking at them purely as fashion accessories, and not as lives in their own right.

"What deserves more public attention is the way pets are sold in Japan," she said.

"We need to ban the trade of newborn kittens and puppies just because they are pretty and sell well."