There is also a making-of video on the advertisement making its rounds on the Internet.
This video can also be viewed at all Wacoal boutiques.
Ayumi's spilling decolletage has got Singaporean fans and netizens wondering if the petite 1.56m J-pop star has had a boob job.
Wrote Arashi on the same forum: "It does look photoshopped, since Ayu isn't exactly known for her bodacious curves..."
Added local fan John Ng, a 28-year-old investment banker: "For her age, she looks very good. But in the photos, she looks bigger, no?"
Ms Lillian Lee, a 23-year-old secretary, agreed: "Her face is very pretty but we all know she is a very petite girl.
"All the past photos I've seen of her she only looks normal-sized."
Other fans attribute Ayumi's new assets to clever photography and posing.
Netizen Imuya wrote: "Ayu is not like Beyonce or something.
"But with the right push-up bra and good positioning, I can see how Ayu could achieve a healthy cleavage without much help from photoshop."
Apart from Ayumi's figure, fans are also questioning why she is doing a lingerie ad.
This is Ayumi's first foray into the lingerie market.
She has previously endorsed make-up, jeans, handphones, sports drinks and electronic products.
After all, the singer, who has been in showbiz for 11 years, has usually relied on her music videos and album covers to sell her sexy image.
Shooting a lingerie ad tends to be the route taken by newbies hoping to break into the entertainment scene.
Said netizen Kyayu on A-H.net, a forum dedicated to the J-pop star: "This is a very nice picture... I'm just surprised that she would do this.
"I really never thought she would start doing lingerie ads."
Added another netizen called Milkycat:
"Never in my life would I imagine Ayu to be a spokesperson for lingerie...
"All I can say is 'WOW'."
Said Singaporean fan, retail manager Claudia Low, 26: "I didn't think Ayumi would do lingerie ads because she's such a big star already, she doesn't need it.
"But I guess she's doing it before she gets too old."
In the Wacoal press release, Ayumi said: "I am honoured to be selected as the spokesperson for Wacoal.
"Wacoal's pursuit for perfection and functionality is akin to my belief and attitude in work."
Perhaps Ayumi's campaign has to do with competition from the new threat to her J-pop throne - label mate and pop rival Kumi Koda.
The 27-year-old broke into the market in 2001 with a Japanese-turned-English single, Take Back, which peaked at No. 18 on the US Billboard Hot Dance Music chart.
But she only made it big in 2005 with a sexy promotional campaign and has been flaunting her shapely curves in skimpy outfits since.
That same year, a 23m-tall promotional poster of the Japanese bombshell clad in a cleavage-baring, peacock feathers-adorned dress was placed at a crowded intersection in Tokyo's Shibuya district by her record label Avex Trax.
How Kumi beat Ayumi
Fans lapped it up and Kumi (right) proved that sex sold.
She went on to triumph over Ayumi for two years running - winning the Nihon Golden Disk Award in 2006 and 2007, Japan's version of the Grammy Awards - to become Japan's best-selling pop act.
Furthermore, Kumi is famous for being well-endowed.
Once, she turned up as a guest on a popular TV show, Music Station, clad in just leopard-print lingerie.
She also happily flaunted her figure in her fourth album Secret, in 2005, which contained a 28-page booklet with pictures of her posing topless.
Kumi's willingness to sell her sexpot image also made her a champion of a "if you've got it, flaunt it attitude among young Japanese women", noted Amy Chozick in the Wall Street Journal.
Perhaps Ayumi is trying to play catch up?
Whether her hot new lingerie pictures will outdo Kumi's next project remains to be seen but J-pop fans on JapanForum.com are sticking with Ayumi.
Wrote Kanabros: "Kumi's pretty darn sexy, but I fell in love with Ayumi's voice."
Dethbydisco commented: "I kind of like both, but Ayumi wins! I think she's got more going for her!"
Added Singaporean Rachel Ong, 25, a marketing executive: "Not everyone can pull off lingerie. And she does it in such a classy way. If you have what it takes, why not?"IF YOU'VE got it, flaunt it.
That seems to be the message from Japanese pop superstar Ayumi Hamasaki.
The 31-year-old singer is fronting a new ad campaign for lingerie brand Wacoal.
And her fans are buzzing about her generous cleavage being splashed all over the ads, which is part of a campaign called Trust Me.
The advertisements are out in magazines and at Wacoal boutiques and various departmental stores all over Singapore.
They are also available in other countries in Asia.
Plans are in the works for the lingerie-clad Ayumi to grace the giant billboard outside Tangs along Orchard Road, says Ms Elaine Seah, public relations director of Brand Incorporated, Wacoal's public relations agency.
The sexy ads show the singer frolicking about in bed with just a bra and a pair of panties.
This article was first published in The New Paper on Jan 23, 2009.