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!

That's the guy from yesterday.
إنّه نفسه من الأمس
Das ist der Typ von gestern …
Es el de ayer.
Es el de ayer.
C’est l’homme d’hier…
È lui quello di ieri.
É o cara de ontem...
Это тот самый, вчерашний...