The "elite student in music room 2" turns out to be Haruki's delinquent classmate, Kazusa Touma.  With his characteristic pushiness, he tries to get her to join the light music club.  But his pushiness backfires, and only makes her more annoyed.  Setsuna gets irritated... no, involved, and approaches Kazusa secretly.
She's the school idol.
Sie ist das Idol der Schule.
Es la estrella de la escuela.
Se supone que es la estrella del instituto.
C’est l’idole de l’école, non ?
Ela é a estrela do colégio.