|Lives:||Azabu-Juuban, Minato-ku, Tokyo|
|Family:||Mika Kayama (daughter)|
|First Anime Appearance:||Shingo's Innocent Love! A Sorrowful French Doll|
|First Manga Appearance:||N/A|
|First PGSM Appearance:||N/A|
|English Name:||Yoshiko Cassidy|
|Actors:||Miyoko Aoba (anime), Wendy Lyon (dub)|
Yoshiko Kayama was a character who appeared only in episode 18 of the anime. She was famous for her doll-making skills, and had a widely promoted doll exhibition at the Juuban Art Museum. Her daughter, Mika Kayama, was also following in her mother's footsteps as a doll maker.
Yoshiko was very supportive of her daughter's craft, and tried to promote her work whenever possible. For this reason, she invited Nephrite, who was disguised as a doll enthusiast, into her home to meet Mika, which allowed him to use the girl as part of his plans to gather more energy.