Ushio Okazaki is the daughter of Tomoya and Nagisa Okazaki. Following her mother's death in childbirth, Ushio spends her early years in the care of Akio and Sanae Furukawa, Tomoya having been stricken by depression following his loss. Ushio goes on a trip with her father after five years, and Tomoya decides to raise her after having met with his grandmother. However, Ushio is soon overcome by illness, and dies in Tomoya's arms. However, due to her having created the Illusionary World, her and Nagisa's lives are spared by Tomoya's actions when the light orbs allow him to return to his meeting with Nagisa.