Tenshi, Ei-chan, and Shiratori all attend Kawagoe Academy. One day, they get pulled into the orbit of former conductor Haruo. He drags them into his newly founded boys choir where they suddenly find themselves performing a song in front of an audience!

Where's the suspicious person?!
!أين ذاك الشخص المشبوه؟
Wo ist der Verdächtige?!
¿Dónde está el sospechoso?
¿Dónde está el sospechoso?
Il est où, cet intrus ?
Dov'è il sospetto?
Cadê o cara suspeito?
Где тот странный мужик?!