Danda Kyouko goes to a small piano school.
That school is at Hirano Kanade's own house, it's a small cozy school with only one old upright piano.
That day something was different however.
Unfamiliar piano music was echoing from the classroom...
Kyouko opened the door although with a strange feeling.
The thing that was in front of her was...?

(Translated from the official site)