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!

It's a big cardboard box.
إنّه صندوق كرتونيّ كبير
Es handelt sich um eine
größere, begehbare Box.
No es más que una caja de cartón grande.
No es más que una caja de cartón grande.
Une grosse boîte en carton.
È uno stanzino di cartone ondulato.
É uma grande, para se concentrar!
Да, большая такая, картонная.