Dear Friends

Rina is introduced as a high-school student who believes friends are unnecessary and only useful in times of need. Her family life is distant: her father doesn't seem to care much and her mother is overprotective. This mindset sets up her later reckless social life and her initial emotional isolation.

Rina spends evenings at a Shibuya club with Yousuke, Hiroko, and Emi. In the opening scene, she borrows Hiroko's boyfriend for sex, which infuriates Hiroko. Yousuke falls for Rina, but their relationship never becomes intimate and they merely flirt.

She obtains money under false pretenses by claiming she is pregnant and forcing a donor to pay for an abortion (not Hiroko's boyfriend). She spends it on a bottle of Dom Perignon and sprays champagne over everyone at the club. After this, she collapses on the dance floor, marking the start of her health crisis.

Rina is diagnosed with non-Hodgkin lymphoma and is hospitalized for an indefinite period. Her family does not visit, while one classmate Maki makes an effort to reach out and reconnect. The hospital becomes the setting where her worldview begins to crack.

Maki reveals that they were friends in primary school, but Rina does not remember her. Maki uses this chance to reach out and re-establish a bond, offering companionship she has been denying herself.

Kanae, a young girl with leukemia, tries to befriend Rina. Rina persists in her belief that friends are unnecessary, resisting Kanae's attempts to connect.

Rina's health declines as chemotherapy takes its toll: her hair falls out and she grows paler. She learns Kanae had leukemia and died after a bone marrow transplant failed, a sobering reminder of the fragility of life.

Cancer spreads to her left breast, requiring a mastectomy. Frustrated and desolate, Rina resolves to commit suicide by jumping from the hospital rooftop.

Before she can jump, Maki stabs herself in the chest and declares that she will share the pain with Rina and that she won't let her lose a friend. Her act is motivated by a mix of suicidal tendencies and a fierce desire to keep Rina alive.

Hiroko and Emi visit Rina in the ward. Hiroko discards a love letter from Yousuke and claims she and Emi had a three way with him. Emi concedes this, acknowledging the complicated dynamics surrounding Rina.

After treatment, Rina is discharged and tries to return to her party lifestyle, but she cannot fully revert to her old self. She goes back to the club, where Emi apologizes for the hospital visit and Hiroko's involvement; Yousuke becomes wary after seeing Rina's mastectomy scar.

Rina goes back to the hospital rooftop to jump, but is stopped by the head nurse. The nurse explains that Maki wanted her to live. Then another nurse wheels a zombie-like Maki in a wheelchair onto the rooftop, revealing a terminal neurodegenerative disease and telling Rina that the only reason she still lives is to meet friends like her.

Moved by these moments, Rina fully recovers from cancer, applies to nursing school, and becomes a nurse. She dedicates herself to caring for Maki during her final days.

Maki dies after three months of being cared for by Rina. The loss is tempered by Rina's resolved purpose as a caregiver, shaping the rest of her life.