Angel's 3Piece!

Kyou Nukui, a high school student, has been absent from classes to focus on composing music, which he shares online under the pseudonym "HibikiP." His friend "Kiriyume" illustrates the music, but Kyou deviates from his usual style with the song TR03, posting it anonymously as "me" without a drawing. He receives a polite email praising the music and is surprised by the sender's insight into his identity. He meets the email's authors, three elementary school girls, Jun, Nozomi, and Sora, who ask for his help to hold a concert at their orphanage, an old church.