外人♡あゆコミュの2006

Hamasaki's thirty-ninth single Startin' / Born To Be... was released on March 8, 2006. The single debuted at #1 on the Oricon chart with sales of 116,000, and thus broke the record of most #1 singles in Japan for a solo (female) artist previously held by Seiko Matsuda. It was her 26th #1 single. However, Seiko still holds the record of the most consecutive No.1 singles for a female artist, a record that she has been holding for two decades and not likely to be broken anytime soon (Ayumi has 16 consecutive number 1 singles as of July 2007).

She then embarked on the "Ayumi Hamasaki Arena Tour 2006 ~(miss)understood~" which spanned three months with its first date in Saitama on March 11, 2006 and made its last stop at Yoyogi on June 11, 2006. With 30 concerts, it was her largest tour to date. The last concert of the tour was recorded and released on DVD in November. It entered both the music-DVD and general-DVD charts at the top position.

Hamasaki released her 40th single "Blue Bird" on June 21, 2006. "Blue Bird" scored the #1 position on the daily Oricon chart. Just a single day after going on sale, Oricon confirmed the single had outsold its competition already, securing the weekly #1 for Hamasaki's 15th consecutive number one single and 27th total number one single, selling 160,572 copies in its first five days.

Hamasaki released her eighth full-length album, Secret on November 29, 2006. Originally, the album was slated to be released as her second mini-album with seven songs overall. The speculation proved to be false when her official website announced a change of plans and that Secret would be a full-length album in October 2006. The album was completed on November 8. Hamasaki also raised media attention for the music video of "Jewel," which shows 100 million yen (almost $900,000 U.S. dollars) worth of diamonds, jewels, and Swarovski crystals. The video is one of the most expensive videos ever made. On that same day, she sang "Jewel" in an orchestra version on 130,000,000 Choose Best Artist 2006. The album debuted at the top spot of the Oricon weekly chart with first week sales of 386,280 copies, outselling the number two album for a large 160,129 copies.

Secret is also believed to be Hamasaki's most successful album yet in worldwide sales. Not only did Secret top the Japanese charts, the album was an instant number-1 hit in countries as Taiwan, Singapore, Hong Kong and China surpassing the (miss)understood international success, being in Taiwan the #1 Japanese album of the year with a 3.54% of total sales.