- January 26: The Morning Musume and Heike Michiyo fanclub Hello! is created.
- April 3: Otsuka Aina is born.
- April 6: Katsuta Rina is born.
- May 3: Yasuda Kei, Yaguchi Mari, and Ichii Sayaka join Morning Musume as the second generation.
- May 14: Horie Kizuki is born.
- May 28: Sayashi Riho is born.
- June 12: Murota Mizuki is born.
- July 28: Okamura Rise is born.
- August 5: Suzuki Kanon is born.
- August 28: Mikame Kana is born.
- October 30: Tamura Meimi is born.
- October ?: Tanpopo is formed.
- November 5: Ogata Risa is born.
- November 24: Yamagishi Riko is born.
- December 1: Miyamoto Karin is born.
- December 30: Uemura Akari is born.
- January 28: Morning Coffee - Morning Musume (major debut)
- February 15: Sotsugyou ~TOP OF THE WORLD~ - Heike Michiyo
- May 27: Summer Night Town - Morning Musume
- July 1: Daikirai - Heike Michiyo
- August 5: Karasu no Nyoubou - Nakazawa Yuko (debut)
- September 9: Daite HOLD ON ME! - Morning Musume
- October 25: Dakedo Aishisugite - Heike Michiyo
- November 18: Last Kiss - Tanpopo (debut)
- December 2: Odaiba Moonlight Serenade - Nakazawa Yuko & Takayama Gen
- March 25: Teenage Dream - Heike Michiyo (debut)
- July 8: First Time - Morning Musume (debut)
- December 12: Nakazawa Yuko Dai Isshou - Nakazawa Yuko (debut)
- September 14: Morning Musume's 1st anniversary.