When 30-year-old Japanese salaryman Takahisa Kobayashi places his head on the lap of an attractive young woman, he is thinking of his mother.

The summer kimono covering her thighs brushes against his face as he lies on the tatami mat floor and briefly looks into her elegantly made-up eyes.

A traditional alcove displays an ornate umbrella from years gone by, soothing away the memories of the garish neon of Tokyo's streets as 24-year-old Amane talks softly to her customer.

Then she begins scraping wax from his ears with a sharp bamboo stick.

"I'm coming here to relax my mind. Most Japanese associate ear cleaning with their childhood," said Kobayashi, who manages a consulting company in Tokyo.

As a young child, he recalls sitting on his mother's lap as she gently removed the daily build-up.

"My wife occasionally cleans my ears but that is different without the traditional Japanese-style room and its tatami matting."

Kobayashi is one of up to 150 people -- most of them men -- who come to the flagship parlour of Yamamoto Mimikakiten (Yamamoto Earpick Shop) in Tokyo's bustling Akihabara district every day.

The parlour, one of 11 in the chain, has 16 rooms and is often fully booked, by customers paying 2,700 yen ($35) for a half-hour session.

Amane -- who declined to give her real name -- wears a light summer kimono, known as a yukata, as she welcomes her clients with a cup of green tea.

She lays their heads gently on her lap and talks to them as she selects the right kind of metal or bamboo pick to remove the particular wax she is trying to excavate.

"Customers say it is healing and comfortable, with some even falling deep asleep and snoring during the session," said Amane.

Amane, who also works part time as a masseuse, first encountered the chain as a customer, a rare woman among the men who make up the bulk of its clientele.

Store manager Satoru Takahashi says even though only five percent of customers are female, the men who come know that there are limits to the services on offer.

"After the ear-cleaning, the girls blow in the customers' ears to remove any remaining dust. Lots of guys ask the girls to blow a lot," he said.

A sign in the reception sets the boundaries: "We are not a salon offering sexual services. We will stop ear cleaning whenever there is an act that offends women."

But the chain implicitly acknowledges that customers might find favourites among the all-female staff, with regularly updated blogs showing photographs of those working at the salon (www.yamamotomimikaki.com/index.php).

Ear cleaning has boomed in Japan since it was de-regulated six years ago and people without medical training were allowed to begin offering it as a service.

Shops have sprung up all over the larger cities, and while Yamamoto Mimikakiten offers a very straightforward service, other chains cater to more exotic tastes -- women wearing maid outfits will spend several hours working on a customer's ears.

Like the bars where hostesses coyly serve their male customers and laugh obligingly at their jokes, or the coffee shops where mirrored floors tantalisingly reveal untouchable waitresses without underwear, mimikaki occupies the grey area in Japan between innocence and commercial sex.

The so-called "floating world" where men pay for the ministrations and company of women has its roots in the culture of geisha, highly trained artists whose skill in music, dance and conversation was -- and in rare cases, still is -- highly prized by those with the money to pay for it.

For those working at the higher end of the industry there are very good rewards -- a highly trained geisha could expect to earn perhaps hundreds of thousands of dollars a year -- and would enjoy the respect and protection of people around her.

But for those at the other end, the "floating world" can be an altogether darker place, where a regular customer can mutate into a dangerous obsessive.

Two years ago, the mimikaki industry was rocked by the murder of 21-year-old Miho Ejiri, who was stabbed to death alongside her grandmother by a customer whose advances she had rebuffed.

For Amane, her part-time job is a place where she can offer comfort and help to those who come to her, in an environment where she does not feel threatened.

She sees nothing sexual in what she offers; for her it is all about relaxation and making someone's life better.

"Customers come here to be healed," she said.