Ryouko appears (sings/talks) in the following CD singles.

2001.05.23	Galaxy Bang! Bang! (LACM-4014)	Song
2002.02.28	Yume Mitai Angel Tai (LACM-4047)	Song
2002.10.23	Galaxy Babanga Bang! (LACM-4074)	Song
2002.12.25	Hai! Hai! Hai! [Pita Pita Angel A] (LACM-4080)	Song
2005.10.26	Moonlight Love (KICM-3116)	Song
2006.03.01	Million Love/Rainy Beat [Kage kara Mamoru] (SVWC-7336)	Song
2006.05.24	Ramune Characters Collection vol 5 (NECM-12122)	Song
2006.07.26	Inukami! Character Collection CD 6 (KICA-766)	Song/Talk
2007.08.22	Hito toshite jiku ga bureteiru (KICM-3152)	Song
2007.09.26	Zessei Bijin (KICM-3153)	Song
2008.01.23	Kuusou Rumba (KICM-3162)	Song
2008.02.27	Marionette (KICM-3163)	Song
2008.05.21	Crossing Days (LACM-4502)	Song
2008.07.23	Hatena de Wasshoi (LACM-4511)	Song
2008.09.10	Hidamari Sketch X365 Character Song vol 4 (LACM-4528)	Song
2008.10.22	Tsuki to Orgel (LACM-4535)	Song
2009.06.26	Amagami Character Song Vol. 1 (TRCD-10089)	Song/Talk
2009.07.23	Ringo Mogire Beam (KICM-3192)	Song
2009.11.25	Piece of Love (LACM-4667)	Song
2010.01.27	Dekiru Kanatte Hoshimittsu (LASM-4044)	Song
2011.10.26	Euphoric Prayer (LACM-4871)	Song
2011.11.23	Kimagure Jan Ken Pon (LASM-4118)	Song
2012.10.24	Koi-Ken Music Box (LACA-15241)	Song
2012.10.24	Open Canvas (LASM-4148)	Song