The music has been created mainly by composers from Taiwan and Japan, with a variety of songs featuring vocals and instruments that cover a wide range of genres. [The story] Deemo is a mysterious being who lives alone in a castle, playing piano for himself. One day, a little girl with no memory falls from the sky, breaking his solitude.

Deemo feels the need to help her return to her world. While searching for a way to send her back to the sky, Deemo notices a small sapling that grows the more he plays music. If Deemo manages to make it grow into a tree tall enough to reach the window on the ceiling, then she might be able to go home. As the two interact, Deemo learns what it means to have a friend. What awaits them when the little girl regains her memory? This is a slightly strange, touching story...