Revenge of a Mother (1970)

Bong-sam abandons his sick wife Sun-im and young son Gwi-dong for a rich widow named Yeon-wol. Sun-im dies and Gwi-dong is raised by Yeon-wol, who severely abuses young Gwi-dong. Sun-im's soul, which cannot leave this world, stays to protect her son. She asks Yeon-wol to be a good mother to Gwi-dong but Yeon-wol takes no heed, and her abuse continues. Sun-im kills Yeon-wol and asks a wandering monk to take in her son, then leaves for the other world.