Genres: Romance, tragedy (partially), drama, fantasy
Phase 1: Male protagonist Tomoya Okazaki, who in his final year at highschool, finds his future bleak and has a pessimistic outlook in life.
Phase 2: Tomoya meets the female protagonist, Nagisa Furukawa, who is also in her senior year. Although peculiar, she has a goal before graduation – to revive the drama club and perform a play in the annual school festival.
Phase 3: Through many hardships and helping their friends overcome their difficulties, Tomoya and Nagisa worked together and finally succeeded in reestablishing the drama club. In the process, Tomoya and Nagisa grew closer – they’ve developed a bond that far exceeds that of friendship, but neither of them had the guts to confess to the other.
Phase 4: Nagisa performs the play in the annual school festival and is applauded for her excellent performance. Throughout the play, Tomoya finally realizes that he is in love with Nagisa while she performs. After the performance, Tomoya tells Nagisa to meet up in the drama club room, in which he finally confesses his honest, genuine feelings to Nagisa. Nagisa accepts Tomoya’s confession and the two became one.
Phase 5: Due to Nagisa’s frail body, she missed too many days of school and had to repeat her senior year. Tomoya, having already graduated, makes the decision to move out of his house to avoid his father, whom he has a strained relationship with and moves into Nagisa’s house. While Nagisa goes to school, he works at her family’s bakery to earn himself an income. When Nagisa finally graduated from their highschool, Tomoya marries Nagisa.
Phase 6: Nagisa is pregnant with Tomoya’s child and despite countless warnings given by Nagisa’s doctor due to her weak condition, she is determined to give birth to the child, whom the young couple named Ushio. When Ushio is brought into the world, Nagisa failed to survive the delivery.
Phase 7: Having lost the one and only love of his life, for the next 5 years, Tomoya lives an unhealthy life by becoming addicted to smoking and alcohol, and working non-stop at his electric company, with Ushio sent to the Furukawa household to be taken care of by Sanae and Akio, Nagisa’s mother and father, respectively. Sanae eventually comes up with a plan to trick Tomoya into going on a trip with his daughter alone, in which she succeeds.
Phase 8: Being the cynical jerk Tomoya is, he constantly acts way too bluntly towards Ushio and has shown zero care as a father. Tomoya and Ushio journey to the northern flower fields by train, and he meets Shino Okazaki, his grandmother. Shino tells Tomoya that Naoyuki, his father married his girlfriend Atsuko (Tomoya’s mother) at a very young age and died shortly after their marriage; mirroring the relationship of Nagisa and Tomoya. Tomoya, finally having realized that his lack of care is causing Ushio to suffer, approaches his daughter and tells her about his wife. As Tomoya is narrating his past, he cannot help but bawl due to the fact that losing Nagisa is way too much for him to bear and that he has to yet overcome his loss.
Phase 9: Tomoya and Ushio have reconciled their relationship as father and daughter, but alas, good times don’t last forever. Ushio is later shown to have inherited her mother’s disease. Knowing that she barely has any time left, Ushio requests Tomoya to take her out on another trip. Although initially reluctant, Tomoya eventually decides to give in to Ushio’s request. In the icy cold while navigating through the winter snow, the single parent and her dying daughter attempted to make their way to the train station. Ushio, unable to bear the pain anymore, dies in her father’s arms while weakly uttering, “I love you, daddy.” Having lost everyone that is dear to him, Tomoya breaks down, falling into the deepest bowels of despair.
Phase 10: The audience sees a robot made of junk and a girl that bears a striking resemblance to Ushio, with the only difference being that her stature suggests that she is in her teenage years. It is revealed that the world where the robot and the Ushio lookalike reside has already ended, with those two as the sole survivors. The audience also learns that this world is a parallel world to that of the world that much of Clannad’s story took place in. The goal of the robot and the “teenage Ushio” is to find a way to transport themselves out of this world before winter comes. In the end, all their efforts ended up in vain, but not all hope is lost - the girl that looks like Ushio reveals to the robot that the light orbs that were gathered in the parallel world, obtained by Nagisa and Tomoya by helping their friends out when they were in need, can pile up to create a miracle, in which its effect is up to the discretion of the wisher. The Ushio double also informs the robot of an important piece of info in her last dying words, “Until we meet again, daddy.” In actuality, the robot is actually Tomoya, having lost his memories and human form.
Phase 11: Tomoya is sent back in time retaining all of his memories – good and bad, courtesy of the light orbs. As he is walking up the mountain, he sees Nagisa. Tomoya initially makes the decision to ignore Nagisa as he knows he will eventually result in her death, along with his daughter following her mother’s fate. However, Tomoya realizes that he cannot live his life without Nagisa. He turns back and embraces Nagisa, shocking the latter, who also retains her memories with her lover. The young couple confesses to each other that “falling in love with you was the best thing that ever happened in my life”. Suddenly, Nagisa and Tomoya are sent forward in time, right before Nagisa is about to give birth to Ushio. Tomoya, assuming that Nagisa will succumb to disease once again, closes his eyes and starts grieving. However, a miracle occurred and Nagisa survives the delivery. Tomoya, overcome with joy, embraces his wife while they enjoy the scenery of the light orbs that evoked the miracle outside of their apartment window. As the show is brought to its conclusion, Tomoya, Nagisa and their daughter are seen to be living happily ever after.