Japan is the only country in the world in which pets outnumber children. Kids and pets are closely linked in Japan: as the number of newborns shrinks, the number of cats and dogs is rising.

Not that you’d know it walking the streets of Tokyo. Despite the rising number of cats, it’s rare to see them out and about. Dogs are a more common sight (and often to be seen tucked up in prams, swaddled in coats and blankets like substitute babies).

The near invisibility of the city’s pets is probably down to their owners’ reluctance to let them out. Generally speaking, cats aren’t allowed out because their crap is considered antisocial. As for the city’s dogs, most of them are ‘toy’ breeds rather than working dogs, which is to say they’re bred to loll around the house not doing much but looking pretty. They don’t get walked much and many are what might be called ‘involuntary hikikomori’ (hikikomori are people who refuse to leave their rooms for fear of interaction with others).

While millions of solitary, solo-living single city dwellers would love to have a pet to keep them company, they are quite expensive to buy and feed. Besides, dogs are inclined to spend the day howling if left alone all day, which your neighbours won’t appreciate. Cats are more independent, but if you don’t let them go outside, their litter tray will need to be cleaned every day.

People who love cute pets, but are put off by the dirt, smell and expense that comes with owning one may be interested to know about ‘Oideyo Bongo’, a ‘robot toy’ dog from Bandai Namco Group Megahouse.

‘Bongo’ is the latest in a long line of what are effectively animal-shaped, battery-operated toys. At first sight, Bongo might look a bit gimmicky - his legs are basically a disguise for his wheels, which make him look like a bit like a vacuum cleaner. But it’s hard not to be impressed (and touched) by the way he follows his owner around the room.

Bongo is modeled on the dachshund, so he has an elongated body that shrinks and expands like an accordion, which will delight kids (not that his owner is likely to have any). Bongo can wag his tail and his ears prick up when you ask him a question (such as what the Japanese government should do about the country’s declining birth rate). He also has a small but delightful repertoire of doggy movements and can even bark at strangers. Bongo can be yours for 12,800 yen plus tax (which is about a tenth of the price of a real-life puppy).