Her introduction to tidiness came from watching her mother struggle to maintain orderliness in their home. "As my mother was a housewife, I, too, became very interested in housekeeping," Kondo says.

In fact, she became so keen on it, she volunteered to clean her siblings' rooms and couldn't resist tidying her friends' rooms, too, when she visited. It wasn't long before she was dipping into home magazines for ideas. By the time she began the equivalent of secondary school, Kondo was devouring all the books on tidying up that she could lay her hands on.

That led to a successful career as an organisational consultant in Tokyo.

Kondo has elevated tidying to an art with her "KonMari Method", the moniker created by combining her family and given names. More than a set of utilitarian rules for tidying up at home or in the workplace, it is also a guide to acquiring a mindset for creating order and becoming a tidy person.

"In Japan, people believe that cleaning their rooms brings good luck. But if your house is cluttered, the effect of polishing the toilet bowl is going to be limited," Kondo says. "The same is true of fung shui: it's only when you put your house in order that your furniture and decorations come to life."

But it wasn't until Kondo wrote a book about her approach to decluttering that she became something of a celebrity in Japan, and is now a regular guest on television and radio shows.

Titled it has become an international hit with more than two million copies sold worldwide. The English translation was released at the end of last year.

The core of Kondo's housecleaning philosophy is to discard everything that doesn't bring joy to a person's life.

"The process of assessing how you feel about the things you own, identifying those that have fulfilled their purpose, expressing your gratitude, and bidding them farewell is really about examining your inner self - a rite of passage to a new life," she writes. "The yardstick by which you judge is your intuitive sense of attraction."

The first step is to divide all the stuff in your home into categories, starting with clothes, handbags and shoes, and then move on to books, papers and what the Japanese call - "small articles; miscellaneous items; accessories; gadgets or small tools, parts or attachments".

Although most people know clutter is connected to having too many possessions, they often don't realise how much stuff they actually own, Kondo says. And our failure to accurately grasp the extent of our possessions results largely from our complex storage methods.

"The secret to maintaining an uncluttered room is to pursue ultimate simplicity in storage so that you can tell at one glance how much you have," she says.

Although she has laboured long and hard to simplify storage, Kondo still comes across things she had forgotten about in a closet or drawer: "If my storage were more complex - for example, if I divided my things into three levels according to frequency of use or according to season - I am sure that many more items would be left to rot in the darkness."

Clutter, she believes, is most efficiently dealt with in one fell swoop, and the trick is not to be half-hearted about what to discard: "I recommend aiming for perfection just once."

Kondo is aware her advice might sound counterintuitive, but says there are only two ways to get rid of clutter: "Deciding whether or not to dispose of something and deciding where to put it ... if you can do these two things, you can achieve perfection."

Minimalism and neatness are, of course, revered in Japanese culture, but these ideals are largely associated with traditional rooms, particularly the room where tea ceremonies are held, she says.

So it shouldn't come as a surprise that clutter is a problem in a densely populated nation such as Japan, where housing is a constant issue.

As the average Japanese became richer during the boom years of the 1960s, they began to acquire more things. Later, the growth of dollar stores, big-box outlets and internet shopping further fuelled consumption.

"People tend to buy goods that seem convenient but really aren't," Kondo says. "We tend not to consider what is truly important for ourselves and the way we truly wish to live."

At the same time, the traditional Japanese virtue of cherishing one's possessions continues to hold sway, especially among the country's swelling elderly population.

While helping her clients put their homes in order, Kondo says there are two things that constantly surprise her: the unusual items that people keep and their sheer numbers.

One client had 60 toothbrushes, neatly arranged in boxes in a cupboard below the bathroom sink.

"They looked like a work of art," she says. "I found myself pondering whether she would go through one a day if she brushed her teeth too hard, or if perhaps she used a different brush for each tooth."

Another client kept 30 boxes of plastic kitchen wrap in a cupboard above the kitchen sink. The record stock of toilet paper Kondo encountered was 80 rolls - a hoard that the client attributed to her "loose bowels".

But by far the biggest surprise she encountered was a stockpile of 20,000 cotton swabs. By her calculation, "if my client used one swab a day, it would take 55 years to use up her supply".