 The first four albums released include songs by Aya Hirano as Konata Izumi, Emiri Katō as Kagami Hiiragi, Kaori Fukuhara as Tsukasa Hiiragi, and Aya Endō as Miyuki Takara; these four albums were released on September 5, 2007.The next four released include songs by Shizuka Hasegawa as Yutaka Kobayakawa, Minori Chihara as Minami Iwasaki, Kaori Shimizu as Hiyori Tamura, and Nozomi Sasaki as Patricia Martin; these four albums were released on September 26, 2007.The ninth album was a duet with Kaoru Mizuhara as Misao Kusakabe, and Mai Aizawa as Ayano Minegishi which was released on October 24, 2007.