Ouji Masamune

Ouji is a student in the third year of Private Aria Academy. He is popular with girls, particularly Kanade who has a crush on him. Also he's the school idol, and the leader of the group called the "Musical Princes". He has Feelings for Siren/Ellen when she was helping her with her problems in Episode 25

The Concert and Hibiki's hate of music
Dan Hojo is helping Ouji practice for the concert later that night and comments that Ouji is not really playing. Hibiki gets mad remembering when she was told the same thing. Later after the concert is attacked by a negatone both of them understand what Hibiki's father meant.

Meeting Siren
Ouji saves Siren from being run over by a truck when she's in cat form. Siren says she never been held by anyone before and starts to develop a crush on Ouji but her mission for Mehpesto gets in the way of this.

Ouji's birthday
Ouji's birthday was hosted at Lucky Spoon by the rest of the Musical Princes with the permission of Kanade. But Siren tried to stop him by making him fall in a deep sleep.But later on he still woke up by Cure Melody and Cure Rhythm.Many people greet him with gifts mostly girls.

Relationships
Siren: He showed affection to Siren when she was telling him she was getting bullied. He gave some advice but Siren never knew he showed affection to her. Ouji also saved Siren when she was about to be hit by a car when she was trying to catch a note

Trivia

 * Ouji is the second boy to have many girls like him the other being Fujimura Shougo.
 * Ouji is the only boy who plays in a band
 * He is also the only boy who plays an instument.The Piano