Ishikawa Hideo CDs (singles)
Hideo appears (sings/talks) in the following CD singles.
| 1997.07.19 | Mountain (COCC-14455) | Song |
| 1997.11.01 | Sotsugyou M voice message Katou Yuusuke (CODC-1355) | talk |
| 1998.06.24 | Jewelry Love (TYDY-2117) | Song |
| 1998.12.01 | Heart ha Koukiatsu [E.M.U.] (CODC-1673) | Song |
| 1999.05.01 | Sotsugyou M character CD special 1 () | Song |
| 1999.05.01 | Sotsugyou M character CD special 5 () | Song |
| 2001.12.05 | I.D.E.A. (CPDA-1017) | Song |