For some insight into the ruckus that SoftBank kicked up when it relaunched its mobile phone service with a zero-yen-per-call plan, check out its new ads and compare them with the competition’s. NTT DoCoMo’s ads showcase no less than seven famous personalities (eight if you count female comedy duo Othello as two), each one representing a target demographic. KDDI’s au ads augment popular actress Yukie Nakama with ubiquitous hunk Mokomichi Hayami and a subset of minor but recognizable TV talent.

SoftBank’s ads feature only one celebrity: Cameron Diaz. And while DoCoMo’s ads stress continuity and reliability (“That’s why I’m DoComo”), and KDDI’s make a big deal out of its wide variety of features (each talent represents one), SoftBank’s give you nothing but Diaz. There’s no pitch, no explanation, no jokes. In one, Diaz is in a supermarket, her basket overflowing with stuff; in another she looks businesslike, striding purposely toward the camera. In both she’s talking on her cellphone, and in the print ad she just stands there with the phone to her ear, staring straight at you.

The implication is simple: “We got Cameron Diaz and you didn’t.” It’s a move that’s as cheeky as CEO Masayoshi Son’s shock announcement of the zero-yen plan the day before the start of “number portability” on Oct. 24, which allows cellphone users to switch carriers without changing their telephone numbers.

Portability has been described as a sop to consumers who complain that mobile-phone fees in Japan are way too high. SoftBank Mobile, which trails behind the other two carriers in terms of customers, has been expected to shake up the rigid price structure ever since Son bought Vodaphone earlier this year. Then Son dropped his bombshell Oct. 23 with his yosogai waribiki — unexpected discount.

It was only unexpected to NTT and KDDI. Consumers have been waiting for someone to take the initiative where it counts — in the fee department. The Nov. 4 “be” consumer-interest supplement of the Asahi Shimbun published a survey of almost 3,000 people it conducted before the number portability launch and Son’s announcement. Only 2 percent of respondents said they were planning to change companies, with 18 percent saying they were taking a wait-and-see attitude. The majority surveyed were described by the article as being “cool and frank”: cellphones are just too expensive and most people don’t really care about Internet access and “wallet” functions — they simply want to talk and exchange mail.

The mobile-phone market in Japan is essentially controlled by a cartel, even if it isn’t necessarily an orchestrated one. Part of DoCoMo’s new promotion strategy is to dispel the general image that “DoCoMo’s fees are too high.”

The company’s brochures, printed before SoftBank’s zero-yen announcement, provide a fee-by-fee comparison of the three companies and they’re exactly the same. DoCoMo’s aim is to show that it isn’t any more expensive than the other guys, but what the chart really points out is that there’s no competition.

Thus NTT and KDDI reacted defensively when Son dropped his bombshell. They complained that the defection of customers who wanted to take advantage of the zero-yen plan disrupted their business since it paralyzed computer systems involved in processing applications. They also asked the Fair Trade Commission to look into SoftBank ads that mention the plan, which they said were misleading. According to the fine print it isn’t really a zero-yen plan.

As demonstrated by the Livedoor and Murakami Fund scandals, the media likes nothing better than to stick it to upstarts like Son, who started his Internet services company from scratch, and they had a field day with the fine print issue. Wide show reporters parsed the ads on the air and cried “fraud.”

It was all very disingenuous. Surely no consumer who saw the ad believed that SoftBank Mobile’s services are gratis. An old Japanese saying goes, “There’s nothing more expensive than something that’s free.” Fine print has been around as long as advertising. Whatever liberties SoftBank took were nothing compared to the antics recently revealed in the insurance industry wherein policy holders were led to believe they were covered for things that they weren’t covered for. And what about that consumer-loan company who advertises zero-interest loans? Airlines and travel agencies routinely announce low fares above fine print about surcharges. These surcharges can run into the tens of thousands of, yen depending on the carrier and the ticket price.

Once the people who decided to switch to SoftBank Mobile actually make their applications they surely will learn that the zero-yen program, which allows them to make unlimited calls to other SoftBank customers but only at certain times of the day, comes with conditions. The problem with the plan isn’t so much that it’s misleading, but that like the NTT and KDDI plans it’s complicated. In any event, the plan is only good until January, after which new subscribers pay through the nose like everyone else.

In other words, Son isn’t shaking up the fee structure, which is what consumers really want. He’s simply attracting attention with a limited-time promotional deal, understanding that consumers won’t be fooled into thinking they’re getting something for free, but hoping that they might be fooled into thinking that SoftBank was taking the lead in fee reductions. The only shocking thing about Son’s overall promotional scheme is how far he’s willing to go to make the competition squirm. Cameron Diaz doesn’t come cheap.