Aika, a mother who lost her husband in a car accident three years ago and has raised her only son, Yu, while taking care of her father-in-law who has no other relatives. Yu, who always saw her mother working hard while being chased by her daily life, had a desire to become a full-fledged person and become a filial piety. One day, Yu sees his father-in-law, who should have been sick and lying on the bed, digging into Aika's body, which is devotedly caring for her, with a nasty hand.
