Jeong-hye is given a ten-year sentence after accidentally killing her abusive
husband. In prison, she gives birth to a beautiful baby boy who brings light
into not only her own life but also those of her cellmates, all of whom have
unfortunate stories of their own. Jeong-hye is only allowed to keep her baby
for a short period of time, and the days are counting down quickly.

To earn the chance to be allowed a day out with her son, Jeong-hye
decides to start a prison choir despite not being able to hold a tune herself.
Resistance is high and singing talent low, but the tone-deaf choir slowly find
their groove along with their sense of self as they come together as one. But
the day that Jeong-hye proves herself with the choir is also the day she has
to give up her son.