Morning Musume. OG member Reina Tanaka & Yumemiru Adolescence member Rei Kobayashi are going to make Guest Appearance in Ryusoulger Episode 7. Reina Tanaka & Rei Kobayashi are going to play the roles of Princess Sisters of Planet Cepheus who have got lost on their way to earth. Reina Tanaka is going to play the role of Princess Cardena who makes Ryusoulger to find her sister.
Rei Kobayashi is going to play the role of Cardena's younger sister Feeta.
Because of the cast are Idols, they are going to sing in the TV Series. It is very rare in TV Series (Yes, I have mentioned it as TV Series. So don't come back claiming Kyoryuger Movie) to perform a song especially by Idol.