Cassiopeia

Su Jin is a successful lawyer. After her divorce, she is having a perfect life as a lawyer and mother. She is preparing her daughter, Gina, to study in the United States. Her father In Woo lives with them and takes care of her granddaughter.
Su Jin is suddenly diagnosed with Alzheimer's after a car accident. Her father protects her staying by her side as she starts gradually turning into a young child due to loss of memory and a loving accompaniment begins.
(Source: Wikipedia)