Dear Brother

Nanako has her first day at Seiran Academy. Rei helps her on the bus, and Nanako is instantly captivated by her charm. At school, Nanako meets Mariko, who immediately asks her to be her friend.

Mariko looks out for Nanako before class, and shoves Tomoko out of the way when she finds Nanako. Fukiko comes to Nanako's class and announces three Sorority candidates: Mariko, Kaoru, and Nanako.

An insulting note is posted about Nanako's candidacy for the Sorority on the school bulletin board, announcing to the entire school that Professor Misonoo is not really her father.

Despite missing the selection party, Nanako has her interview, and humiliates herself. Mariko and Nanako realize that anyone could have left the message for Nanako, but Mariko correctly suspects Aya.

Nanako sees Kaoru stops Rei from taking some pills. Fukiko invites Rei into the Sorority House to help out with work, but intentionally injures her hand. Rei demands that Fukiko bandage her bloodied hand, but Fukiko refuses.

The bullying continues: Nanako's gym uniform is stolen and cut to shreds, and Tomoko won't lend Nanako hers.

Depressed from her classmates' bullying, Nanako goes to the school's clock tower to spend some time alone. There, she sees Rei, smoking and throwing knives at a carving of Fukiko in the wall.

Mariko tries to warn Tomoko off Nanako again, but Kaoru comes by and stops her. Fukiko invites Aya to the Sorority House and threatens her to stop bullying Nanako.

Kaoru collapses from chest pains, so Nanako tries to fetch painkillers from Rei. Rei doesn't take the situation seriously, so Nanako slaps her.

Mariko refuses to eat anything until Nanako forgives her, but Nanako is giving her the silent treatment. Kaoru notices Mariko's hunger strike and confronts her about it, angry that anyone would throw their health away when Kaoru herself is so ill.

The Sorority members have a special study session at Fukiko's house. Fukiko invites Rei to join them, telling her to wait under the elm tree at five o'clock, but doesn't arrive.

Nanako calls Kaoru to help take care of Rei. Kaoru arrives at Rei's apartment and slaps and yells at her for her masochistic devotion to Fukiko.

Rei is well enough to go back to school. She confronts Fukiko, but is made docile with a few words. Tormented, she retreats to the clock tower and takes too much drugs.

Nanako desperately tries to escape from Rei, but fails. Rei attempts to stab Nanako several times before regaining her senses and breaking down in tears when she realizes what she is doing.

A Sorority member named Junko Nakaya fails one of her exams due to having been seriously ill, so Fukiko orders her to resign.

Nanako realizes that she has fallen in love with Rei, but is too nervous to say anything. One of her letters to her "Brother" end up in Fukiko's possession and she must face her wrath.

After Nanako accidentally misses her bus stop, Rei takes her to the park. The two spend a happy morning together, and in a burst of emotion, Nanako confesses her love.

Rei refuses to react after hearing Nanako's confession and begins to intentionally avoid her, breaking Nanako's heart. Kaoru, sensing Nanako's pain, tells her to give up on Rei, for "her soul is enslaved by a goddess," referring to Fukiko.

Nanako and Tomoko decide to go to Takehiko's university fair. They invite Mariko, but she is reluctant because she thinks the men will corrupt Nanako.

Nanako, Tomoko, and Mariko go the University Fair with Takehiko and Takashi, Fukiko's older brother. Mariko does her best to protect Nanako from the men, but ends up comically failing.

Mariko and Nanako are invited by Fukiko to her country house for the weekend to help her prepare for her birthday party. There, Nanako goes for a walk near the lake and sees Fukiko playing her violin sadly.

Home from the lake house, Fukiko and Rei visit Ms. Asaka's grave on the anniversary of her death, three years ago. The two are unusually civil; as they part, Fukiko invites Rei to her eighteenth birthday party.

Confused by the events of the party, Rei inquires of Takashi as to why the song upset Fukiko so. It is revealed that, when Fukiko was twelve and Takashi eighteen, Takashi had brought Takehiko Henmi to visit their lake house.

Rei reminisces about the first time she met Fukiko, remembering how, even as a child, her pride had still been admirable. She then overhears two Sorority members telling Nanako to meet Fukiko at the Sorority House suspisciously late at night.

Rei reflects on that double suicide pact that she and Fukiko made shortly after Rei's mother committed suicide, when Rei was soon to be properly adopted by the Ichinomiya family.

Mariko's parents are divorcing and she is traumatized, spending the night at Nanako's home to try coping.

Everyone desperately looks for the missing Mariko, fearing for the worst. This includes both of Mariko's parents and even Mr. Shinobu's girlfriend, who calls her mother and apologizes.

At the Student Assembly, Kaoru asks for the abolition of the Sorority. Rei is horrified at first, believing that it would destroy Fukiko's pride, but ultimately decides that she has to learn to live without the Sorority in order to be truly strong.

Two Sorority members, Ogiwara and Komabayashi, persuade Aya's friends, Miyuki and Megumi, to steal and burn the petitions. Rei stops them. Aya intentionally takes the blame to protect the girls, saying that she'd ordered her friends to do so.

The Sorority members are getting scared as the Petition gains movement and their own members begin signing it. Angered at Fukiko's lack of action of the subject, Ogiwara and Kombayashi decide to take matters into their own hands by confronting Nanako in a broken down building.

Fukiko continues to pretend that nothing is wrong. At the final Sorority meeting, none of the members arrive. Rei attends the meeting instead, and encourages Fukiko to continue with her speech.

Rei dreams of her mother's death, in which Ms. Asaka reveals that Fukiko is her child as well. She was adopted immediately after her birth, depriving her mother of any chance to be near her.

Nanako waits for Rei to pick her up for their date, but soon, everyone finds out that Rei is dead. Nanako, Tomoko, Fukiko, Kaoru, and Takashi go to the hospital to see Rei's body.

The school attends Rei's funeral. Fukiko accepts all of the guests with dignity. Afterwards, she asks for two minutes alone and cries over Rei, telling her that she really did love her, and kisses her.

Two weeks after Rei dies, it is the summer holidays. Kaoru goes for an examination and is told by her doctor that she needs more tests. She reacts badly, thinking she is going to die.

Kaoru tells Nanako that she broke up with Takehiko because of her illness and masectomy, and that Nanako is really Takehiko's stepsister. Nanako's father tells Nanako that she has a stepbrother, and that he loves his son as much as he loves her.

Takehiko is about to leave for Germany, so Kaoru intends to leave him behind for good. Takehiko, Nanako, and Fukiko try to convince her that Rei would have wanted her to live her life to the fullest.

Fukiko has a hallucination where Rei encourages her to find true love. Fukiko is tormented, thinking that Takehiko was the only love she'd ever have, and cries in her brother's arms.