|Birthday||Film: Sunday, 24 December 2006|
Anime: c. February 2006
|Anime debut||White Darkness|
|Relatives||Tomoya Okazaki (father)|
Shino Okazaki (great-grandmother)
|Japanese voice actor|
|English voice actor|
Ushio Okazaki (岡崎汐, Okazaki Ushio) is the daughter of Tomoya Okazaki and Nagisa Furukawa. She is named for her mother, with both of their names using the radical 水. Ushio resembles her mother a lot, and seems to like the Great Dango Family as well. She only appears in the After Story arc of the anime, the beginning of the Clannad opening, and in the movie. After giving birth to her, Nagisa dies. This deeply depressed Tomoya, and he gave up raising Ushio soon after and left her to the care of Akio and Sanae. Tomoya resorts to alcohol and cigarettes to ease his depression.
Five years later, Sanae arranges Tomoya and Ushio for a trip in hope for them to be together again. During this trip, Tomoya meets his grandmother, Shino, and learns about his father's past and the sacrifices he made for Tomoya, which leads him to regret his actions, and he decides to raise Ushio and acknowledge Naoyuki as his father.
Shortly after Tomoya sets things right, Ushio is struck with the same disease as Nagisa and despite the efforts and sacrifices of Tomoya, Akio and Sanae made, Ushio's fever never subsides but actually worsens. In the coming winter, being filled with desperation of wanting to do anything for Ushio, Tomoya brings her for a trip, but she falls unconscious and dies shortly after along with her father who succumbed to his grief. Ushio is then revealed to be the Girl in the Illusionary World. Not wanting her family to suffer from such a cruel fate, she created the Illusionary World in order to meet Tomoya again and collect enough light orbs to make a miracle possible and save their lives.
In the anime, after the truth is revealed, having collected enough orbs, Tomoya manages to turn back time and call out to Nagisa. Ushio's birth then happens again, but this time, Nagisa doesn't die, and she, Tomoya and Ushio live happily together as a family, freed from their tragic fates. This will also happen in the visual novel if you've collected all the necessary light orbs. Asides from Tomoya, who vaguely recalls these memories, no one else seems to remember anything.
In the epilogue, Ushio is shown sleeping under the same tree where Akio begged for Nagisa's life to be saved.