"Kokoro no Ito" tells the story of a deaf woman (Matsuyuki) who has raised her son (Kamiki) with hopes of him becoming a top-class pianist. The son is burdened by her high expectations, but then he learns about her past.

A single deaf mother lives with her son. They share a dream that he will pass the examinations required for him to attend a prestigious music school, which means he has to focus and study. He happens to meet a girl who is deaf and is in a band. Unfortunately, before the friendship could blossom the boy's mother intervenes.—aghaemi