Single
| 29/4/1998 | Aishiteiru Kara (愛しているから) | |
|
1. | Aishiteiru Kara (愛しているから) |
| 2. | You | |
| 3. | Aishiteiru Kara (Original Instrumental) (愛しているから) | |
| 4. | You (Original Instrumental) | |
| 18/11/1998 | Tears in Love | |
|
1. | Tears in Love |
| 2. | Blue Night | |
| 3. | Tears in Love (Backing Track) | |
| 4. | Blue Night (Backing Track) | |
| 17/6/1999 | Arigatou... (ありがとう...) | |
|
1. | Arigatou... (ありがとう...) |
| 2. | Aishiteiru Kara (Sincerely Version) (愛しているから) | |
| 3. | Arigatou... (Backing Track) (ありがとう...) | |
| 4. | Aishiteiru Kara (Sincerely Version) (Backing Track) (愛しているから) | |
| 23/5/2001 | tomoni | |
Buy IT! |
1. | tomoni |
| 2. | Yes I Know | |
| 13/9/2001 | Say Hi!! | |
Buy IT! |
1. | Say Hi!! |
| 2. | Mokuji (目次) | |
| 21/11/2001 | Tenshi (天使) | |
Buy IT! |
1. | Tenshi (天使) |
| 2. | Whisper | |
| 23/1/2002 | Ningen tte Sonna Mono ne (人間ってそんなものね) | |
Buy IT! |
1. | Ningen tte Sonna Mono ne (人間ってそんなものね) |
| 2. | Mou Aisenai (もう愛せない) | |
| 3. | MOONLIGHT SHADOW | |
| 21/5/2003 | Kawaranai Koto ~since1976~ (かわらないこと) | |
Buy IT! |
1. | Kawaranai Koto ~since1976~ (かわらないこと) |
| 2. | tell tell Bouzu (tell tell坊主) | |
| 3. | Kawaranai Koto ~since1976~ (Instrumental Version) (かわらないこと ~since1976~) | |
| 4. | tell tell Bouzu (Instrumental Version) (tell tell坊主) | |
| 24/9/2003 | The Power of Smile / Remember the kiss | |
Buy IT! |
1. | The Power of Smile |
| 2. | Remember the kiss | |
| 3. | The Power of Smile (Instrumental Version) | |
| 4. | Remember the Kiss (Instrumental Version) | |
| 21/4/2004 | so much love for you | |
Buy IT! |
1. | so much love for you |
| 2. | New season ~Yume ni Mukatte Fuku Kaze~ (夢に向かって吹く風) | |
| 3. | i Shiteru (iしてる) | |
| 4. | so much love for you ~Instrumental Version~ | |
| 23/6/2004 | Yume ga Chikara (夢がチカラ) | |
Buy IT! |
1. | Yume ga Chikara (夢がチカラ) |
| 2. | Ningyo no Yume (人魚の夢) | |
| 3. | Yume ga Chikara (Instrumental Version) (夢がチカラ) | |
| 23/2/2005 | dandelion | |
Buy IT! |
1. | dandelion |
| 2. | Boku no Kimochi (僕の気持ち) | |
| 3. | dandelion (Instrumental Version) | |
| 21/7/2005 | time to say goodbye | |
Buy IT! |
1. | time to say goodbye |
| 2. | Shiawase no Hanataba (幸せの花束) | |
| 3. | time to say goodbye (duet "KOKIA & Piano") | |
| 4. | Yuukyuu no Mori ~My Home Town~ (悠久の杜) | |
| 1/1/2006 | Ai no Melody / Cyouwa oto ~with reflection~ (愛のメロディー / 調和 oto ~with reflection~) | |
Buy IT! |
1. | Ai no Melody (original version) (愛のメロディー) |
| 2. | Cyouwa oto ~with reflection~ (調和 oto) | |
| 3. | Ai no Melody (soundtrack ver.) (愛のメロディー) | |
| 4. | Ai no Melody (instrumental) (愛のメロディー) | |
| 16/3/2007 | Arigatou... (ありがとう…) | |
Buy IT! |
1. | Arigatou... (ありがとう…) (the pearl edition) |
| 2. | Utau Hito (歌う人) | |
| 21/11/2007 | Follow the Nightingale | |
Buy IT! |
1. | Follow the Nightingale |
| 2. | say goodbye & good day | |
| 3. | Follow the Nightingale (Instrumental) | |
| 4. | say goodbye & good day (Instrumental) | |
| 28/1/2008 | Tatta Hitotsu no Omoi (たった1つの想い) | |
Buy IT! |
1. | Tatta Hitotsu no Omoi (たった1つの想い) |
| 2. | Umaretate no Shiro (生まれたての白) | |
| 3. | Tatta Hitotsu no Omoi (たった1つの想い) (Instrumental) | |
| 4. | Umaretate no Shiro (生まれたての白) (Instrumental) | |
Altri:
| 18/11/1998 | Ai no Field (愛の輪郭(フィールド) (KOKIA & Kyokou Katsunuma) | |
|
1. | KOKIA - "Ai no Field" (愛の輪郭(フィールド) |
| 2. | Katsunuma Kyouko - "Tenjin no Komoriuta" (天神さんの子守歌) | |
| 3. | Katsunuma Kyouko - "Dear my mother" | |
| 4. | KOKIA - "Ai no Field (Original Karaoke)" (愛の輪郭(フィールド) | |
