Rizumu is a student who goes to the same school as Aira. She was born on September 3, 1997, the same as Aira. She has horrible grades (stated by the girl herself) and even says that getting a 70 would be a miracle for her, but she is very good at dancing and attends a dance school for Prism Stars named "Pretty Top". She seems to be knowledgeable about love from a certain book of hers. She is romantically interested in Hibiki who is a member of Callings, like Shou. As a result, she easily becomes jealous of any girl who seemingly displays an interest in him. She loves to eat almost anything and especially enjoys meat and chocolate. Her catchphrase is "I'm full of energy!".
Rizumu is revealed to be the legendary Prism Queen Kanzaki Sonata's daughter. She always tries to do her best and wants to become the Prism Queen to perform the "Aurora Rising", thinking that it will bring her mother back, who disappeared after performing the legendary jump. Rizumu sometimes tries so hard that she forgets what the Prism Show is really about. She has orange hair and light brown eyes which is noted by Aira's mother to look exactly like how a younger Sonata did.
In "Pretty Rhythm: Dear My Future", Rizumu and Hibiki announced that they were engaged in Episode 28. They got married in Episode 51. Rizumu's song is called "Kokoro Juuden" and was first heard in Episode 12. Her wedding dress is "Pure White Wedding Dress". In the future, Rizumu gets a new little sister.