Watch Aikatsu Friends!: Kagayaki no Jewel Online

The story takes place two years after Aikatsu Friends! with Aine Yuuki now in high school. One day she has an encounter with the mysterious idol Hibiki Tenshou who wears the shining Jeweling Dress.

Aine Yuuki, who is a regular student at Star Harmony Academy's normal division, meets Mio Minato from the idol division, who invites her to join Aikatsu to fulfill Aine's goal to make friends. She also befriends Maika Chōno and Ema Hinata who are also idols. Aine and Mio form a pair to become best friends to become the bright "Diamond Friends". Karen Kamishiro and Mirai Asuku are categorized as "Diamond Friends" and are in the Diamond Class! (Source: Wikipedia)