Her first album, A Song for XX (1999) perched at the top of Japanese music chart Oricon for five weeks, while her sophomore effort Loveppears (1999) also topped the charts.

Since then, she has released 51 singles, sold more than 50 million albums, and is widely regarded as Japanese pop's reigning queen, with the most number one singles of any female solo artist.

And it seems like Ayu, as she is known to her fans, is not about to stop anytime soon, with the release of her 15th studio album Colours in July this year.

She told The Straits Times' Life! in a recent email interview: "I can't picture a life without music. That's how much I love it. I love songs. I love singing."

2) She is deaf in one ear

In 2008, the singer announced on her website ahead of an Asian tour that she has lost all hearing in her left ear.

Writing that her left ear "doesn't work anymore" due to an inoperable condition, she added that she does not intend to give up singing.

"I won't stop. I won't make excuses. As a professional, I would like to deliver the best performance for everyone," she wrote.

It is believed that her condition could be tinnitus, a ringing in the ear that can be caused by constant exposure to excessive or loud noises, reported AFP.

Tinnitus is the same condition that afflicted famous deaf German composer Ludwig van Beethoven.

3) She has had an eventful love life

The crooner has had a prolific dating history, which includes Japanese singer-actor Tomoya Nagase and back-up dancer Maro.

In January 2011, she married 32-year-old Austrian actor and model Manuel Schwarz, whom she had met the previous year on the set of the music video for her ballad Virgin Road. They divorced a year later.

Watch the video here.

In February this year, she married a 26-year-old American medical student.

4) Before singing, she was an unsuccessful model

The Fukuoka native began her modelling career at the early age of seven.

When she was 14, she moved to Tokyo to take on various modelling and acting jobs, but did not find much success.

Standing at a petite 1.57m, she was deemed too short by her talent agency, which eventually dropped her, according to Asian music portal JpopAsia.

After achieving stardom, however, she is now considered a fashion icon, glossing the covers of many fashion magazines like Vogue, Bazaar and Vivi.

She has also been repeatedly crowned by Oricon as the "Most Fashionable Female Artist".

5) She was also a rapper

Hamasaki's first professional music venture was in the rap scene, according to JpopAsia.

In Dec 1995, she released the album Nothing from Nothing under the Nippon Columbia label. When it failed to chart on Oricon, the label dropped her.

It was not until she met Japanese record producer and head of giant label Avex, Max Matsuura, that she was offered the recording deal that shot her to stardom.

The Nothing from Nothing album, rare and released before Hamasaki achieved fame, is now considered a collector's item.