2006 was the year in which Mitsui Aika joined Morning Musume and Konno Asami and Ogawa Makoto graduated from Morning Musume
Members
- February??:
- Rainbow Pink is formed
- Mano Erina, Ogura Manami & Komine Momoka join Hello Pro Egg
- July 16: Shim Soon Min join as a Exchange Student but later withdraws
- July 23: Konno Asami and Ogawa Makoto graduated from Morning Musume
- August 6: Ogawa Makoto officially graduates from Morning Musume
- December 10: Mitsui Aika joins Morning Musume as 8th. Generation member
Singles
- January 25: Ima ni Kitto... In My LIFE - Goto Maki
- Febrary 8: Suna wo Kamu You ni... NAMIDA - Matsuura Aya
- March 15: SEXY BOY ~Soyokaze ni Yorisotte~ - Morning Musume
- March 26: Jiriri Kiteru - Berryz Koubou
- April 12: Sweetoholic - Abe Natsumi
- May 6: Massara Blue Jeans - C-ute (debut indies)
- May 10: Issai Gassai Anata ni∮A.ge.ru♪ - V-u-den
- June 3: Soku Dakishimete - C-ute
- June 7: Glass no Pumps - Goto Maki
- June 10: Onegai Miwaku no Target / Crazy Happy! - Melon Kinenbi
- June 21: Ambitious! Yashinteki de Ii jan - Morning Musume
- June 28: The Stress - Abe Natsumi
- July 2: Yume Kara Samete - Takahashi Ai
- July 9: Ooki na Ai de Motenashite - C-ute
- July 12: Koi Kana - Tsukishima Kilari starring Kusumi Koharu (Morning Musume) (debut)
- July 26: Omae no Namida wo Ore ni Kure - Maeda Yuki
- July 29: Wakkyanai (Z) - C-ute
- August 2: Waracchaou yo BOYFRIEND - Berryz Koubou
- August 9: Ao - Ishii Rika
- September 16: Minna no Ki - Tomoiki Ki wo Uetai (debut)
- September 27: Urara - Nakazawa Yuko
- September 30: Thanks! - GAM (debut)
- October 4: Amasugita Kajitsu - Abe Natsumi
- October 11: SOME BOYS! TOUCH - Goto Maki
- October 18: Melodies - GAM
- October 25:
- Balalaika - Tsukishima Kilari starring Kusumi Koharu (Morning Musume)
- LET'S GO Rakuten Eagles - DEF.DIVA
- November 19: Young DAYS!! - THE Possible (debut)
- November 22: Aisu Crea~m to My Purin - V-u-den
- November 28: Aruiteru - Morning Musume
- December 6: Munasawagi Scarlet - Berryz Koubou
- December 10: Hatsukoi no Kakera - THE Possible
Albums
- February 15: Rainbow 7 - Morning Musume
- March 29: 2nd ~Shimiwataru Omoi~ - Abe Natsumi
- July 5: 3 Natsu Natsu Mini Berryz - Berryz Koubou
- August 23: Country Musume Daizenshuu 2 - Country Musume
- October 24: Cutie Queen Vol.1 - C-ute (debut)
- December 6: FRUITY KILLER TUNE - Melon Kinenbi
- December 13: 7.5 Fuyu Fuyu Morning Musume Mini! - Morning Musume
- December 20: Petit Best 7