On August 12, 2008, it was announced Aki would be leaving the group to pursue a career as a singer-songwriter. The group made their last public appearance with Aki at the Japanese premiere of the "Sex and the City" film. In October, Lina and Reina told fans that they had been in meetings with their record label. They did not discuss the details of the meeting, however, claimed that all would be revealed soon. On October 28, a press release was issued announcing the return of original member, Mina, and an official comeback. They made their first public appearance on Tokudane and a reunion concert and new remix album were announced. The reunion concert was held on January 31, 2009 as a one-night only event at C.C. Lemon Hall in Shibuya, Tokyo. Its success led to announcement of six additional shows turning the concert event into a nationwide tour. On the first night of the tour, their first comeback single, "Rough Cut Diamond" was announced. It was released on July 22, 2009.