Both doramas have heavy feelings and treat subjects as children's absuse and adults that try to help them.
Kimi wa iiko tells the stories of different children who have to undergo different adversities but they end up being pilars for the people who are near them, something similar occurs in Mother.

Both had rotten kids who takes wrong decisions and tell stories about teens in they're grow-up paths.
They left you a sad and bitter taste but a litlle of hope too.