Shōta Machiya, a high school student with an affinity for building rockets, is friends with Asuna Ayase whose father recently was killed. Fumika, along with her talking staff Kanaka, comes to deliver a letter to Shōta which was written by Asuna's father after he died. The letter is addressed to "Ayase's lover", so for the time being Shōta cannot accept the letter until he starts going out with Asuna; in the mean time, Fumika waits for him to confess his love to Asuna. One day close to the launch of his new rocket, Kanaka accidentally leaves the letter behind where Shōta reads it to discover that Asuna killed her own father. Shōta does not believe what he reads and instead seeks out Asuna, only to be killed by her a short time later after Fumika appears

Asuna and Miku move into an orphanage while the police search for the missing Shōta. It is revealed that Asuna was sexually exploited by her father before she killed him. When Shōta's body is found, Asuna decides to cut her hair and leave by train. However, before she can leave, Fumika delivers a letter to her from Shōta. After reading it, she decides to launch Shōta's rocket. Meanwhile, the police have identified Asuna as a suspect in Shōta's murder. Just before the rocket is set to launch, the police confront her on the rooftop. The wind blows a tarp over the rocket, and Asuna rushes forward to cut the tarp away so the rocket can launch. The police misinterpret her intentions and fatally shoot her. The episode ends with Fumika delivering a letter to Miku, Asuna's younger sister

Three friends, Sen, Kotake and Nojima, discuss about jumping — but not dying. Sen, a guy who just smiles and is cheerful kills himself by jumping off his apartment building. His father is desperate to know to how he died, so he takes the students in Sen's class hostage. Fumika shows up and delivers a letter from Sen to Kotake; the letter reveals that Sen jumped because he was in the mood for it. Nojima, who believes that Fumika is Fumika Mikawa, a girl he knew from junior high that shot her own father, runs to the rooftop to confront her.

Fumika attempts to deliver a thick letter to Ran, a high school tennis player, from her mother who walked out on her as a child with another man. However, Ran has hated her mother ever since and does not accept the letter. Fumika follows Ran on her tennis club's training camp and is persistent in delivering the letter to her; Ran finally accepts it, but refuses to read it. Ran injures her ankle while running and has to stay inside the dorm for the rest of the day, but a fire breaks out, nearly killing Ran. Afterwards, Ran reads the letter and discovers that her mother actually went to all of her tennis matches.

Fumika is assigned to deliver a letter to a cat, however she runs into Chiaki, another shigofumi mail carrier, who is also trying to deliver a letter to the cat. However, Chiaki's attempt to catch the cat scares it away. Fumika and Chiaki realize that they have the same task from an elderly couple who owned the cat. They first attempt to lure the cat using catnip. When that partially succeeds, it turns into a chase. During the chase, Fumika notices Fumika Mikawa's body inside a hospital as she passes the window. Upon catching up to Chiaki, they reach the building where the cat lives. It turns out the letters contained keys to open the door to the apartment where the cat's owners lived.

Kōichi Kikukawa is being bullied in his class, and via an Internet message board one of his classmates named Shunsuke Morishita realizes that the person on the message board is actually Kōichi. Before long, Kōichi kills himself, and Shunsuke takes up Kōichi's previous role as the bullied. Shunsuke finally realizes what Kōichi had been going through and is finding it very difficult to go on living. One night while being bullied after school, Fumika shows up and delivers a letter from Kōichi to Shunsuke; in the letter, Kōichi tells Shunsuke that he wants him to suffer since he bullied him too along with the three other guys. After Fumika leaves, the other three guys go back to bullying Shunsuke, and in a moment of desperation, Shunsuke stabs one of them with a nearby screwdriver.

Haruna Kasai, a woman who has been working in an editing firm for three years, is given the chance to become Kirameki Mikawa's new editor for his poetry, of which she is thrilled since she is a big fan of his work. When Haruna goes to meet with Kirameki at his artistically architectural home, she finds him to be rather strange. Meanwhile, Kaname meets with Natsuka to learn more about Fumika Mikawa, and the two follow a map to Kirameki's house. Fumika arrives at Kirameki's home and gives him a letter from a now-dead fan. She pulls out her gun in order to help him remember about the past, but Kaname interferes, causing Fumika to drop the gun. Kirameki picks it up and shoots Fumika.

After Kirameki shot Fumika, Kaname beat him up and locked him in a room. During this time, Fumika heals herself, even causing the blood stain on her clothes to disappear. Fumika then proceeds to tell the others about how she is in fact a second personality of Kirameki's daughter named Mika who was created due to Kirameki mistreating his daughter. Kirameki uses gunpowder from bullets to break out of the room and Fumika goes after him with the intent to finally kill him. She nearly does, but is stopped by Haruna in the end.

After Fumika, Kaname, and Natsuka go visit Fumika Kirameki in the hospital, Chiaki comes by and asks Fumika if she would like to go to an island in the south for a vacation. Much to Kanaka's surprise, Fumika agrees, though does not really know what to do since she has never been on a vacation before. In the inn they are staying at, Fumika and the others meets a girl who is going to a nearby island to visit her grandfather's grave. It turns out that her grandfather was the man who Chiaki had been in love with right up to her death in a car accident fifty years ago. Chiaki and Fumika also go to visit the grave, and Chiaki's finds a stone-engraved shigofumi addressed to her from her former lover asking her to marry him which Chiaki agrees to.

Takehiko Hibiya is a thirty-two year old man who recently quit his job as a graphic designer for a video game company because he felt he was not creating what he wanted to create. He was told by his doctor that he had contracted appendix cancer which could not be cured. Takehiko takes a relative's young daughter named Fumika out to the movies in a neighboring city, but while there gets in some trouble with the police who suspect he abducted Fumika. After he gets released, he is driving home with Fumika when the car breaks down. Takehiko leaves to try to get help, but Fumika comes running after him saying that she did not want to be left alone. Suddenly, a truck comes their way, and Takehiko pushes Fumika out of the way, but he dies from the accident.

Fumika finally wakes from her coma and is greeted warmly by Kaname and Natsuka. Chiaki learns that should Fumika awaken, Fumika the mail carrier would delivery the gun to her other self and would asked to be shot, effectively "killing" her. Fumika's friends try to avoid this by bringing Fumika to their home, and telling Fumika the mail carrier that her other self was transferred to another hospital. The next day, Fumika remembers how she shot her father, and runs out of the house in search of her other self. When the two finally meet for the first time in three years, Fumika hands her counterpart the gun, and she shoots her. Fumika later goes to the police and accuses her father of child abuse.

After implicating her father, Fumika becomes a celebrity at school and on the Internet; people constantly bother her and try to take pictures of her which greatly pains her. With Fumika, the mail carrier, now gone, Fumika and her friends try to go on with life, but find it hard to go on without Fumika. Kirameki's former wife, and mother of Fumika meets her daughter, but tells her that she does not want to be a mother, and leaves her daughter. Following this, Fumika goes to Kirameki's odd house where she is about to kill herself when her counterpart appears and stops her. An argument starts between them, and Fumika, the mail carrier, hits her counterpart a few times. Kirameki's daughter tells her other self that she too wanted to live a normal life, and that she did not really want to disappear, which she agrees too. Kaname, Natsuka (with Kanaka), and Chiaki (with Matoma) arrive at Kirameki's home to find Fumika and her other self crying together on the ground. Fumika goes back to being a shigofumi deliverer, and the other Fumika goes back to living on her own as a high school student.