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!

Don't worry about who can hear you.
لا تقلق حيال من يسمعك
Denk nicht darüber nach,
wer dir zuhört.
T’as pas besoin de penser
à ceux qui écoutent.
Non devi preoccuparti di chi ti sta ascoltando!
Não se preocupe com quem possa ouvir.
Не думай, кто тебя услышит.