Mou Hitotsu no Piano no Mori: Totonou Oto

The spin-off manga centers on Satoshi Mukai, who once competed with Kai Ichinose in the Chopin Competition. Satoshi was so moved by Kai's performance, that he decides to pursue a career in the world of musical tuning. Satoshi needs to survive in an ordinary society while possessing a rare talent.

(Source: ANN)