Antiphona no Seikahime Tenshi no Score Op A

Music is everywhere in the land of Antiphona. This is a story of Miabelle, a young girl who lives in Antiphona and loves singing. The elder sister of Miabelle, Lily, was elected to be a "singing princess" on a famous festival that occurs only once every 300 years, but just before the festival started, the Devil King appeared and stole the voice of Lily.

To help her sister, Miabelle with her friends and puppets forms a singing group "Celesta". Giving lots of performances along their way, the group takes off on an adventure to get back Lily's voice.