When I first visited Japan many years ago, I marveled at the automatic taxi doors. I was intrigued by the auto-toilets that not only flushed for you but also offered rinse and dry functions. I was delighted to find that baggage deliveries could whisk your suitcase home from the airport sometimes faster than you could get there. I loved the network of takkyubin door-to-door delivery services that could transport parcels across the country overnight for a miniscule fee. And I became reliant on the ever-present convenience stores, or combini, that ply coffee, hot meals, toiletries and a mind-boggling array of services around the clock.

But there was a downside to this wonderland of convenience.Returning to the West after any Japan visit, I would find myself walking away from cabs leaving the door hanging open. I would forget to flush the toilet. I would fume at having to carry my own bag or grumble about journeying to a post office and queuing to send something that would take many days to arrive. And unless I was somewhere like New York City, I missed the 24-hour stores.

For anyone interested in the social and economic implications of Japan's voracious demand for convenience, there's nothing like plunging into Tokyo's 24/7 combini network. What you encounter in a typical inner-city store is a mini-United Nations of staff, speaking Japanese and working a seamless, 24-hour cycle. In a large combini I frequent in the central district of Akasaka, there are 20 or so employees and only a few are Japanese. The others come from places including Kazakhstan, Vietnam, Bulgaria and Nepal.

This might suggest a friendly, outward looking society, open to foreigners and eager to cater to a customer's every need. Indeed, Japan's combini culture has been celebrated in business school studies and was recently immortalized in "Convenience Store Woman," a hit novel by a long-time worker in a suburban convenience store, Sayaka Murata.

But dig deeper and you see the social and economic pressures of feeding the 24-hour combini beast. At the heart of combini culture is a vast army of low-paid staff, including a growing number of foreigners, particularly from developing countries, who are willing to work on relatively harsh terms.

You can also see longer term ills of the deep-rooted "convenience mentality" in contemporary Japanese society. Amid an aging population and slowing economy, with increasing reliance on automation, people are forgetting how to do things for themselves.

Japan's convenience culture covers not only gadgets, such as self-operating vacuum cleaners and window washers, but also services. Take the popular Co-op and other grocery delivery services. Every week my Japanese friend fills out a form that offers a range of seasonal ingredients for home cooked meals. A big box is delivered to her door at a specified time, with the fresh ingredients chopped, sliced and neatly packaged with recipes for five or six family dinners. She says it takes her less than 30 minutes to produce tasty and healthy dishes, and happily confesses she could never revert to her old ways of visiting a supermarket and preparing ingredients.

In this context, the evolution of Japanese combini culture provides ample food for thought. Japan redefined the concept of "convenience" in the mid-1970s by transforming the traditional mom and pop corner store into a 24-hour mini-retail operation catering to myriad needs, from a carton of milk and onigiri rice balls to bill payments, theater tickets and even printing postcards and photos. Fierce competition drove the introduction of one service after another -- way beyond the remit or what might be expected of a local store.

Initially based on the U.S.-led 7-Eleven model, the stores became more sophisticated in their offerings, requiring more deliveries, more workers, and more services. What evolved was a multifaceted retail monster requiring a huge workforce. With nearly 60,000 stores operated by the seven biggest chains, the estimated total number of employees runs to way over a million, most of them part-time.

The problem now is the high price of such convenience, including difficulties recruiting workers willing to accept low pay and part-time status; the challenges of training; the costs of running supply networks; and growing dissatisfaction among franchisees about the 24-hour cycle.

In the ultimate irony, market leaders 7-Eleven and FamilyMart are breaking the previously unshakable 24-hour opening rule to experiment with shorter hours. Admittedly they are focusing on just a tiny handful of stores. But that is just the beginning. The move could trigger a rethink of labor practices and the entire mechanism of the 24/7 combini supply and distribution network.

More significantly, it could eventually shake up Japan's "convenience mentality." When they find their local combini closed, perhaps people will cook for themselves, walk to a supermarket or post office, or procure theater tickets online. In other words, the decline of combini culture could be very convenient - not least to remind people how to do things for themselves.

Gwen Robinson is editor-at-large of the Nikkei Asian Review.