| Date | Title | Amazon | Oricon | Note | |
| 1980/04/01 | Hadashi no Kisetsu | 12 | |||
| 1980/07/01 | Aoi Sangoshō | 2 | |||
| 1980/10/01 | Kaze wa Akiiro/Eighteen | 1 | |||
| 1981/01/21 | Cherry Blossom | 1 | |||
| 1981/04/21 | Natsu no Tobira | 1 | |||
| 1981/07/21 | Shiroi Parasol | 1 | |||
| 1981/10/07 | Kaze Tachinu | 1 | |||
| 1982/01/21 | Akai Sweet Pea | JP | 1 | ||
| 1982/04/21 | Nagisa no Balcony | 1 | |||
| 1982/07/21 | Komugiiro no Mermaid | 1 | |||
| 1982/10/21 | Nobara no Etude | 1 | |||
| 1983/02/03 | Himitsu no Hanazono | 1 | |||
| 1983/04/27 | Tengoku no Kiss | 1 | |||
| 1983/08/01 | Glass no Ringo/Sweet Memories | JP | 1 | ||
| 1983/10/28 | Hitomi wa Diamond/Aoi Photograph | 1 | |||
| 1984/02/01 | Rock'n Rouge | 1 | |||
| 1984/05/10 | Jikan no Kuni no Alice/Natsufuku no Eve | 1 | |||
| 1984/08/01 | Pink no Mozart | 1 | |||
| 1984/11/01 | Heart no Earing | 1 | |||
| 1985/01/30 | Tenshi no Wink | 1 | |||
| 1985/05/09 | Boy no Kisetsu | 1 | |||
| 1985/06/24 | DANCING SHOES | 1 | |||
| 1987/04/22 | Strawberry Time | JP | 1 | ||
| 1987/11/06 | Pearl-White Eve | 1 | |||
| 1988/04/14 | Marrakech | 1 | |||
| 1988/09/07 | Tabidachi no Freesia | 1 | |||
| 1989/11/15 | Precious Heart | JP | 2 | ||
| 1990/04 | All the way to Heaven | UK only | |||
| 1990/07/15 | The Right Combination | 28 | duet with Donnie Wahlberg | ||
| 1990/10/01 | who's that boy | US only | |||
| 1990/11/21 | We Are Love | JP | 16 | ||
| 1992/02/05 | Kitto, Mata Aeru... | JP | 4 | ||
| 1992/08/01 | Anata no Subete ni Naritai/Shinin' Shinin' | JP | 31 | ||
| 1993/04/21 | Taisetsu na Anata | JP | 7 | ||
| 1993/05/21 | A Touch of Destiny | JP | 51 | ||
| 1993/11/10 | Kakowareta, Ai-jing | JP | 63 | ||
| 1994/05/11 | Mō Ichido, Hajime kara | JP | 22 | ||
| 1994/12/01 | Kagayaita Kisetsu e Tabidatō | JP | 12 | ||
| 1995/04/21 | Suteki ni Once again | JP | 22 | ||
| 1996/04/22 | Anata ni Aitakute (Missing You)/Ashita e to Kakedashite Yukō | JP | 1 | ||
| 1996/04/24 | Let's Talk About It | JP | unreleased in Japan | ||
| 1996/05/17 | I'll Be There For You | US | JP | 35 | duet with Robbie Nevil |
| 1996/11/18 | Sayonara no Shunkan | JP | 5 | unreleased in Japan | |
| 1996/12/10 | Good For You | ||||
| 1997/04/23 | Watashi Dake no Tenshi (Angel)/Anata no Sono Mune ni | JP | 5 | ||
| 1997/12/03 | Gone with the Rain | JP | 28 | ||
| 1998/06/17 | Koisuru Omoi (Fall In Love) | JP | 34 | ||
| 1998/11/26 | Touch the LOVE | JP | 66 | ||
| 1999/10/27 | Kanashimi no Boat | JP | 27 | ||
| 2000/05/17 | 20th Party | 17 | |||
| 2000/06/07 | Shanghai Love Song | 37 | |||
| 2000/06/14 | Unseasonable Shore | 35 | |||
| 2000/09/27 | True Love Story/Sayonara no Kiss o Wasurenai | 7 | duet with Hiromi Go | ||
| 2000/11/29 | The Sound of Fire | 46 | |||
| 2001/06/20 | Anata Shika Mienai | 30 | |||
| 2001/11/14 | Ai Ai Ai (100% Pure Love) | JP | 49 | ||
| 2002/06/05 | Suteki na Ashita | JP | 29 | ||
| 2002 | all to you | Billboard Dance Chart 19th, unreleased in Japan | |||
| 2002/12/17 | just for tonight | JP | Billboard Dance Chart 15th, unreleased in Japan | ||
| 2003/06/04 | Call Me | JP | 17 | ||
| 2004/05/26 | Aitai | 12 | |||
| 2004/07/07 | Smile on Me | JP | 18 | duet with Crazy.T (Takaaki Ishibashi) | |
| 2005/02/02 | Eien Sae Kanjita Yoru | JP | 34 | ||
| 2005/08/24 | I'll Fall In Love | US | JP | 30 | |
| 2005/09/21 | Shiawase na Kimochi | JP | 28 | ||
| 2006/04/26 | bless you | JP | 29 | ||
| 2006/05/24 | WE ARE. | JP | |||
| 2007/05/23 | Namida ga Tada Koborerudake | JP | 38 | ||
| 2007/08/01 | Manatsu no Yo no Yume | JP | 36 | duet with Takashi Fujii | |
| 2007/11/21 | Christmas no Yoru | JP | 34 | ||
| 2008/03/19 | Hanabira Mau Kisetsu ni | JP | 32 | ||
| 2008/06/25 | Love Is All | JP | 32 | ||
| 2008/10/22 | Ano Kagayaita Kisetsu | US | JP | 30 | |
| 2010/04/21 | Idol Mitai ni Utawasete | JP | 16 | as Princess Seiko with Yazima Beauty Salon | |
| 2010/05/05 | Ikutsu no Yoake o Kazoetara | JP | 12 | ||
