On the way to school one day, Tomoya Okazaki meets a strange girl talking to herself named Nagisa Furukawa. Later in the day, Tomoya has a conversation with Nagisa during lunch and learns that she is repeating her last year of high school, and wants to join the now-disbanded drama club. After school, Tomoya goes to Nagisa's family bakery and meets her parents; he is invited to have dinner with them.

Tomoya runs into Fuko again at school, and she tries to invite him to her older sister's upcoming marriage ceremony, but Tomoya is not interested. Tomoya gets Youhei to help reform the drama club by bribing him with bread from Nagisa's family bakery. Nagisa tries to get the help of Ryou and Kyou in reforming the drama club, and Tomoya even tries to ask Tomoyo and Kotomi if they would like to join; Tomoyo is trying to become student council president, and Kotomi does not give an answer. Tomoya and Nagisa later go see Fuko about the club, and he discovers from Nagisa that Fuko is supposedly unconscious in a hospital.

More people from school are not able to see Fuko anymore and now even those close to Fuko in the past are beginning to forget about her. First Youhei forget after he goes to see her in the hospital, followed by Kyou and Ryou. Tomoyo manages to remember with Tomoya's help however. Later, Youhei manages to remember Fuko for a moment, but is unable to remember any more. Tomoya and Nagisa buy Fuko a birthday party set to cheer her up. When they get back to the bakery, they discover that Nagisa's father has forgotten Fuko, and while Nagisa's mother has not forgotten completely, she cannot see her anymore. Tomoya and Nagisa decide to take Fuko back to school for now.

The girl in the Illusionary World is dying in the snow, and the robot regrets having her take the journey. The girl can finally hear the robot, and tells him that they once existed in another world. As she hums the tune of "Dango Daikazoku", the Illusionary World starts to collapse. As the robot is swept away, the girl calls him "Papa" and disappears with the world. Back at the hill, Tomoya calls after Nagisa, and she is glad that he did so. Nagisa brings Tomoya through time, and together the voices of the robot and Tomoya note the end of his long journey. Tomoya awakens to Ushio's birth, but this time, Nagisa miraculously survives. After Nagisa watches Tomoya give Ushio her first bath, she and Tomoya see that countless orbs of light are floating throughout the city outside the window. They both sing to Ushio and from then on, Tomoya and Nagisa experience a happy life raising their daughter together, finally free of their cursed fate.