Kotarou awakes on the Moon (Though he currently thinks he's still on the Earth) and enters the city but finds no means of life. He goes to the hill site where he sees Kagari on her knees staring at a sheet made of lines (The Theorem). When Kotarou approaches her she waves her ribbons in the air to keep him away, when Kotarou speaks to her she speaks back, but her advanced language harms his ears.
While Kagari is still researching, Kotarou approaches her and confesses that he just wants to be friends with her; she is almost won over by his words but he makes the mistake of calling her 'baby'. As a response, Kagari holds him into the air with her ribbons and squeezes his body, clearly showing her anger; she then cuts off his head. After that, each time Kotarou tries to impress her, she either cuts off his head or set him on fire. However, Kotarou's persistentness wears her down and she decides to give him a chance, by drinking some of the coffee he made. When Kotarou peeks at her theorem, its knowledge makes him almost pass out and he accidently head-butts her; Kagari decides not to kill him out of good will. When Kotarou feels that he needs to become smarter in order to interact with Kagari, he rewrites his mind and begins to accend into the peak of existence, but is unable to come back down; Kagari pulls him down with her ribbon.Kagari leaves her theorem, searches for Kotarou and finds him in the city. They dance in the moon light with characters in the back ground; during the dance Kotarou disrupts the rhythm and throws Kagari off tempo, she corrects her footing and and does the same to him as revenge; sometime after Kotarou and Kagari waltzing together, Kotarou faints/dies and has to reconstruct himself. While continuing her research, Kagari senses a palpable blood-lust and becomes very afraid, Kotarou appears and comforts her. The blood-lust manifests into a small black familiar, kotarou attacks the familiar but it dodges and heads for Kagari, Kagari tries to defend with her ribbons but the familiar twists its body in the air and break through her defence. Before the familiar can kill Kagari, Kotarou kicks it into a tree and stabs it with his aurora blades. He takes a look at Kagari's theorem and learns that the familiar was sent by Sakura Kashima to kill Kagari in order to prevent her from causing humanity's re-birth. Over the next few days/years/centuries (Time fluctuates differently on the Moon) more familiars come; some try to kill Kagari by leading Kotarou away from her. Kotarou tells her that the only hope for her survival is to finish her theorem and states that they need to get the club back together. Kotarou uses Kagari's Theorem to summon the heroines of Rewrite along with Yoshino and his Wolf Pack in order to protect Kagari. Kagari speaks to Kotarou after he sets up her defence; with a look on her face that says "I've given up, I'm sorry". Kotarou tells her that she did her best and adds to her theorem, "I hope to see you again someday. -Tennouji Kotarou". Kagari has a stroke of inspiration and is able to finish her theorem. Kagari watches Kotarou about to start his million year journey, she thin fuses with the theorem (Turning into a bud-flower which will later grow into a tree, as a result) and begins applying the theorem. While she slowly grows into a tree, her defense is nearly wiped out by the shear number of familiars. Dinosaur-familiars fall down from the sky onto her, Sakuya appears and kills them with ease; he takes the responsiblity of being Kagari's air defense. When the last of the heroines are killed and a large number of familiars fall from the sky, Sakuya changes into his Final Familiar Form and dies while defending her. Kotarou shuts off his humanity and does his best to defend Kagari, but even 'he' cannot handle their large numbers. He is torn to pieces while the familiars claw at her tree-trunk, but before they are both destroyed Kagari manages to finish applying her theorem. She absorbes Kotarou and all of the familiars into the theorem and begins to send them to the Earth. Kagari thanks Kotarou for loving someone as selfish as her and sends him on his 'million-year journey'.
Terra Route Edit
She is seen, transparently at the end of the route, smiling as Kotarou and the heroines approach her.