Rika appears (sings/talks) in the following miscellaneous CDs.

1998 04.21	Sotsugyou III Vocal Collection (COCC-14992)	Song/Talk
1999 02.24	Voice Theater Series 6 Uwase no Genma (TYCY-10011)	Talk
2000 04.28	Denshin Mamotte Shugogetten (MACM-1097)	Talk
2007 03.09	Riviera Drama CD The Precious Chapter (VGCD-76)	Talk
2008 05.28	Tindharia no Tane (KDSD-00234)	Talk