Hitsuji to Hagane no Mori

Overview

Tonomura, a high school student in Hokkaido, meets piano tuner Itadori by chance and aspires to become a tuner himself. After graduating from vocational school, he begins working as a tuner at the music store where Itadori works. With the help of his instructor Yanagi, Tonomura gains experience, but an encounter with a pair of talented twins changes him... A warm and beautiful story that delicately depicts the growth of a young man who is lost and worried, but moves forward into the future. (Source: Shogakukan, translated)

Source: AniList