Both stories confront the concept of childhood innocence and the psychology behind acts of cruelty committed by children.
Both films have a similar context but different reasons for killing. In Confessions the teacher performs acts of revenge towards students as she suspects that some may have killed her daughter. Whilst in Lessons of Evil, he kills students for his own sake.
Both movies contains violence scenes, child abuse at school and mothers revenge. Both movies worth watching!
They're both a collection of stories that are both fantastical and chilling. Neither are exactly horror, but both are horrifying. They're great for a lover of psychological horror. The stories are connected in Confessions, but that's a minor difference. The feel and setting of both films is similar.