A 10th grader. He is the leader of the popular top idol unit M4 and the top student of the Boys' Division. He is Guest's childhood friend. Usually, he acts cool because he's an idol, but in front of Guest, he shows different sides of himself, like teasing or acting a bit spoiled. He worries about Guest and looks out for them. He actually loves Guest very much, but he can't quite bring himself to say it.

He is particularly close to Subaru among the M4 members, often teasing him about his relationship with Guest. When M4 announced their solo activities, it was decided he would go on an Asian tour with Subaru. He is always attentive to his fans, and his popularity among women is exceptionally high even within M4.

The younger brother of Yozora Kasumi (a member of the girls' top idol unit S4/S5) and the older brother of Mahiru Kasumi. He and Mahiru's friend, Koharu Nanakura, are interested in each other. However, in the second year 'Star Wings' arc, every time he and Koharu start to get into a good mood, he is habitually knocked unconscious by a wary Mahiru's knife-hand strike.

A 10th grader. He is reliable but marches to the beat of his own drum.

Koharu's best friend and Laura's idol rival. She belongs to the Flower Class. She is often teased by Subaru.

Yume Nijino's idol rival. She belongs to the Flower Class.

The younger sister of Asahi and Yozora. She is friends with Koharu Nanakura. She has long harbored a desire to surpass her older sister. She belongs to the Moon Class.

She entered Four Star Academy with Yume Nijino and is very knowledgeable about S5. She and Yume are like best friends. She belongs to the Flower Class.

The first member of S5. The top idol of the Flower Class. She is the closest friend to Guest.

The second member of S5. The top idol of the Bird Class.

The third member of S5. The top idol of the Moon Class.

The fourth member of S5. The top idol of the Wind Class.