| background vocals | Al『Love Again』(2001.11.21 WPC6-10179) |
| Background Vocals | Al『EXPANSION』(2000.08.23 HDCA-10046) |
| Female vocals | Al『非情のライセンス』(2000.09.27 UUCH-1003) |
| 涙のパラシュート | Chorus | Al『P.S.RIHO』(1993.09.17 PCCA-00478) |
| Believe in your way | Chorus | Maxi『女神の舞』(2000.08.23 AVCT-30027) |