Ushio is Nagisa and Tomoya's daughter. After giving birth to her, Nagisa dies.After Nagisa death Tomoya gave Akio and Sanae Ushio to take care of. five years later Sanae arranges Tomoya and Ushio for a trip in hope for them to be together again. During the trip Tomoya decides to take care of Ushio. While Ushio was living with her dad she asked Tomoya what was her mom like Tomoya did't anser but he told her to ask
Sanae and she answer she did ask but did not get an answer. When they went to visit Sanae and Akio. Also to get ushio things and apologize and thanking them for all their hard work raising Ushio for him. During a few month later Tomoya and Ushio went to visit her grand parents(Nagisa parents) ushio came out of the washroom and said i can't go and she faints they quickly called the doctor. The doctor said it was the same disease as Nagisa. Ushio was never allow to go outside during that time she was at home with her father Tomoya quit his job to be with her. Ushio last wish was to go on a trip with her dad during winter.so Tomoya brings her for a trip, but she falls unconscious half way and dies. in the Illusionary World Ushio ask Tomoya to create a miracle and save Nagisa and themselves and he did and it was a happy ending nagisa never died and Ushio too