Cassiopeia.

Su-jin who tries to pursue a perfect life as a successful lawyer, single mother and daughter, plans to send her daughter Gina to study abroad in the United States, where her ex-husband lives. When Su-jin gets busier with work, Su-jin's dad, In-woo moves in to help Su-jin take care of Gina. The three live together for some time, until one day, Su-jin gets into a car accident and receives an unexpected diagnosis.