2007–present: Foray into Asia

On February 28, 2007, Hamasaki released A Best 2, a pair of compilation albums containing songs from I am... to (Miss)understood. The two versions, White and Black, debuted at the first and second positions on the Oricon weekly charts, making Hamasaki the first female artist in thirty-six years to hold the top two positions on any Oricon album chart. At the end of 2007, the pair became Japan's fifth and seventh best-selling albums of the year respectively.
In support of A Best 2 and Secret, Hamasaki held the four-month-long Tour of Secret from March to the end of June. She performed not only in Japan but also in Taipei, Shanghai, and Hong Kong, making Tour of Secret her first tour with stops outside Japan. As a result, the concerts became highly anticipated, and tickets for the one in Taipei sold out in two hours; tickets for her Hong Kong concert sold out in three hours.
the writing of Hamasaki's ninth studio album, Guilty (January 2008), was not an emotional experience for her, nor did it have a set theme. However, she said later that the album's tracks appeared to tell a story. Most of the songs were dark; the album had a notable rock tinge. It contained some upbeat dance tracks and ballads, though the latter also had rock overtones. With first-week sales of around 432,000 copies, Guilty peaked at the number-two position on the weekly Oricon charts, making it Hamasaki's first studio album not to reach the top. The album's singles, however—"Glitter/Fated", "Talkin' 2 Myself", and Hamasaki's first digital-only single, "Together When..."—all reached the top of their respective charts. Finally, Guilty was later released as a digital album in twenty-six countries outside Japan, nineteen of them Western nations. That, along with Hamasaki's decision to employ western DJs such as Armand van Helden for her 2008 remix albums Ayu-mi-x 6 -Gold- and Ayu-mi-x 6 -Silver-, has been interpreted as her first step into a global market.
In a January 8, 2008 entry on her TeamAyu blog, Hamasaki revealed that an inoperable condition, possibly tinnitus or Ménière's disease, had caused complete deafness in her left ear. She disclosed that she had been diagnosed with deafness in 2006 and that the problem dated back to 2000. Hamasaki stated that she wished to continue singing, and that she would "not give up" on her fans and that "as a professional", she wanted to "deliver the best performance for everyone".
To celebrate her tenth anniversary in Avex, Hamasaki held her second tour of Asia, Asia Tour 2008: 10th Anniversary. The portion of the tour held in Japan spanned seventeen concerts and lasted from April until June; the stops outside Japan were again held in Taiwan, Hong Kong, and Shanghai. Hamasaki's forty-third single, "Mirrorcle World", was released on April 8, 2008. To commemorate her tenth anniversary in the music industry, the single was released in two versions, the second B-side containing a remix of either "You" or "Depend on You". "Mirrorcle World" became yet another number-one single for Hamasaki, making her the only Japanese female solo artist to have a number-one single every year for ten consecutive years. On September 10, 2008, Hamasaki released A Complete: All Singles, a compilation album that includes the A-sides of all her singles along with previously unreleased footage from her A-nation concerts. Hamasaki's forty-fourth single, "Days/Green", will be released on December 17, 2008, in two different versions; the "Days/Green" version will contain an updated "Love: Destiny", and the "Green/Days" version will contain an updated "To Be".