TOKYO, Japan — There can be fewer places more amenable to nicotine addiction than Japan. The idea of smoking as a socially unacceptable habit has yet to gain currency, smoke-free bars and restaurants are a rarity and cigarettes, at around 300 yen (about $3.45) a pack, are surprisingly cheap.

But Japan’s reputation as a smokers’ paradise faces its toughest challenge for decades with the introduction this autumn of a price hike that will take the price to above 400 yen.

The increase, which comes into effect Oct. 1, is a sign of a shift in attitudes as Japan’s progressive government attempts to rein in soaring medical costs by hitting smokers where it hurts — in the pocket.

There are other signs that attitudes are hardening in a country where cancer kills one in three people, with lung cancer the biggest single killer among the disease’s various forms.

Cigarette packs carry bigger health warnings, although they are not nearly as graphic or prominent as those in Canada and Britain. The introduction of Taspo (tobacco passport) ID cards has made it more difficult for minors to get their fix from cigarette vending machines, while Kanagawa prefecture became the first of Japan’s 47 prefectures to prohibit lighting up in schools, hospitals and other public buildings.

The new mood of intolerance comes against a backdrop of falling tobacco consumption as health warnings and financial considerations have the desired effect.

Japan Tobacco, the world’s third-biggest tobacco firm with a 65 percent share of the domestic market, has seen sales by volume drop every year since 1999. The market is now shrinking by about 4 percent a year, says Japan Tobacco, which sells around 100 brands.

The smoking rate among men dropped to a record low of 36.8 percent in 2008, from 46.8 percent in 2003, according to the health ministry. Among women, the rate has fallen from 11.3 percent to 9.1 percent over the same period.

October’s price change combines a tax hike with a price rise by tobacco manufacturers hoping to offset an expected drop in sales.

Although Japan is the fourth biggest consumer of tobacco by volume after China, the United States and Russia, Japan Tobacco concedes that social and demographic changes are militating against cigarette smoking.

“The number of younger adults is declining, the number of elderly people is increasing, and yes, there are health concerns and fewer places where smoking is permitted,” said Hideyuki Yamamoto, general manager of Japan Tobacco’s media and investor relations division.

“We opposed the tax increase but the government has made its decision so we have to live with it. Instead, we will concentrate on innovation and improving our products in consultation with our customers.”

As conventional cigarette smoking declines, Japan Tobacco is hoping to expand its range of other forms of nicotine delivery, including the recently introduced Zero Style Mint, the world’s first smokeless cigarette.

“These will complement cigarettes, not replace them,” Yamamoto said.

Campaigners agree that the price hike is a step in the right direction, but doesn’t go nearly far enough. Even at 400 yen (about $4.60), a packet of cigarettes will still be about a third the price charged in Britain.

“We want a pack of cigarettes to cost at least 1,000 yen [about $11.50],” said Bungaku Watanabe, director of the Tobacco Problem Information Center in Tokyo. “Tobacco is still far too cheap in Japan.”

Watanabe says Japan’s reluctance to enforce smoking bans and raise prices to levels comparable with those in the United States or Britain stems from the finance ministry’s 50.2 percent stake in Japan Tobacco, which contributes about 1 trillion yen (about $11.5 billion) in tax revenue a year.

Close ties between bureaucrats, politicians and tobacco growers mean it is unlikely that Japan will consider another steep price rise or enforce widespread smoking bans.

“Japan must be the only country in the world where tobacco regulations are devised by the finance ministry,” said Watanabe. “That should be the job of the health ministry. Laws are not made with health concerns in mind, but to protect the tobacco industry.

“We want to turn Japan into a place where it is very difficult to buy a pack of cigarettes. But that is a long way off.”

As a smoker of eight years, Tomo Sekizawa acknowledges that it is getting harder to indulge his habit.

The 28-year-old Tokyo waiter can no longer take cigarette breaks at work and a ban on smoking on the street near his restaurant means he must escape during quiet moments to a smoking room several floors away.

“I think it’s a little too strict to ban smoking on the street, but then again I can see why some people object to smoking outside,” he said. “As long as there is a place for me to go, I can live with that.”

But he will not be among the smokers expected to consider quitting when the price hike is introduced: “I know the government is trying to make a point about the health dangers of smoking. But as long as the price stays below 500 yen [about $5.75], I have no intention of giving up.”