The story proper begins by switching back to an earlier stage in the life of the man, Masayuki Saeki in 2004.
He is strict, well organized, hard working, devoted to his job, and sets very high standards for himself and his subordinates.
He starts inexplicably forgetting things - appointments, details of his work, and his knowledge of the layout of Tokyo.
What follows through the rest of the film is a tragic, emotional and very human portrayal of the suffering and the decline of this once powerful, soaring man to that of a pitiful state that resembles a second childhood as the disease wears him down.
Inevitably, tensions surface between Masayuki and his wife and daughter, and it reaches the point where Emiko's life revolves around taking care of her debilitated husband.