Nippon Television Network Corp. has been skillfully inserting commercials into the late-night drama “Wonder Tours” that began broadcasting in September.

When a woman who plays a radio celebrity in the drama moves a switch, a red “CM” appears on the right side of the screen, and the program shifts to a driving scene in which two performers talk about their vehicles.

The effort by NTV is a challenge to conventional commercials, which are increasingly failing to keep the attention of TV viewers.

“Rather than halting programs to run conventional commercials, I thought the new CM would be interesting,” said Kundo Koyama, a broadcasting writer who planned the program. Broadcasting and advertising officials are paying attention; they want to see if this will keep viewers from skipping commercials.

Kazuya Toda, a producer at NTV, said that behind their attempt to run ads simultaneously with programs is the traditional drop in audience during commercials.

“The per-minute audience rating usually drops several points,” Toda said, but no such drop has been seen in the new approach.

Chikao Minami, chief of advertising at Nissan Motor Co., which is sponsoring “Wonder Tours,” said: “The new ad is remembered even though it is not shown so often. It has been quite effective.”

More than half of the people who use digital video recorders skip at least 80 percent of ads when watching programs they have recorded, according to a Nomura Research Institute Ltd. report released in May.

The report caused a stir because the popularization of DVRs could adversely affect the business model of commercial broadcasters, which don’t charge viewers to watch programs and instead make money through ad revenues.

Dentsu Inc., Japan’s largest advertising company, on the other hand, announced the results of a survey in Britain showing that even in households with DVRs, real-time viewing and listening hours are increasing without commercial skipping.

Yet in Japan, data suggest that compared with households without DVRs, those having them spend fewer hours on real-time viewing.

Sensing a crisis, all members of the National Association of Commercial Broadcasters in Japan began to broadcast “CM of CM” by popular entertainer Aya Matsuura in August, informing audiences about profitable goods and the latest fashions, and proclaiming the importance of ads as a form of entertainment.

Companies are continuing ways to ensure their commercials are not ignored.

In a tieup with Asahi National Broadcasting Co., Shiseido Co., a major cosmetics firm, last summer started airing 54 kinds of ads in which young entertainers like the Ungirls use Uno — a cosmetic brand for men — to transform themselves.

Immediately after that, their cosmetics sales jumped three times higher than predicted. Takahiro Hayashi, chief of advertising and strategy at Shiseido, said, “CMs can be viewed naturally if we don’t repeatedly use product names and instead make the ads interesting.”

But many problems remain. Integrating ads into programs, including by using them as small props in dramas, may invite criticism that such an approach is unscrupulous if too excessive. Other new kinds of commercials meanwhile cost too much to replace existing ads.

Even amid broadcasters’ competition with the Internet and the rising use of multichannel TVs, terrestrial broadcasting’s relative superiority will be unshaken for a while.

“We can gather an overwhelming number of customers at one time,” said Takahisa Ishii, a director at the sales planning and development department of Fuji Television Network Inc.

But Hikaru Kobayashi, managing director of the Japan Advertisers Association, expressed concern about the worsening ad environment.

“Commercials will be buried amid a flood of information,” he said.

Dentsu estimated TV advertising expenses have leveled off over the past few years. In 2004, such expenses totaled 2.044 trillion yen, accounting for 35 percent of total ad outlays.