Shōko Makinohara manifests in two distinct temporal states: one as a middle school student and another as her older self from the future. The younger Shōko, approximately 13 years old and standing 4'11" (150 cm), possesses long black hair with bangs and light blue eyes, typically dressed in a white and blue middle school uniform featuring a blue skirt and red bow tie. The older Shōko, around 18 years old and 5'2"–5'3" (158–160 cm) tall, shares similar facial features but exhibits greater maturity, often seen in Minegahara High School's brown vest/blazer uniform with a red tie or a white dress that later reveals a surgical scar between her breasts. Born with severe congenital heart disease, Shōko endured frequent hospitalizations starting in elementary school. This condition prevented her from envisioning a future, exemplified when she could not complete a fourth-grade assignment about her life plans while her classmates did so easily. Her poor health caused significant distress for her parents, whom she felt obligated to please despite her illness. Two years before the main events, the older Shōko encountered Sakuta Azusagawa on Shichirigahama Beach while he grappled with his sister Kaede's Adolescence Syndrome. During this meeting, she shared her philosophy that "life is here for us to become kinder," expressing her daily goal to be slightly kinder than the day before. She encouraged Sakuta to embrace this mindset, noting his unique understanding of pain could make him exceptionally compassionate. This interaction established her as Sakuta's first romantic interest. In the present timeline, the middle school Shōko met Sakuta and Mai Sakurajima during a rainstorm while shielding an abandoned cat with her umbrella. After Sakuta adopted the cat (named Hayate), she visited his apartment regularly to check on it. During one hospital visit, she confided in Sakuta about her heart disease and the emotional burden it placed on her parents. The older Shōko reappeared during Sakuta's grief over Kaede's memory loss, treating his reopened chest scars. She later revealed these scars resulted from a temporal paradox: her existence relied on a heart transplant from Sakuta, who would die in a future traffic accident on Christmas Eve. When Sakuta resolved to sacrifice himself to save her, Mai intervened and died in his place, becoming the donor instead. This created an alternate timeline where Shōko survived with Mai's heart, but Sakuta, devastated by Mai's death, accepted the older Shōko's offer to travel back in time and prevent the accident. This intervention erased Shōko's survival, as neither she nor Sakuta died to provide the transplant. To resolve the paradox, Shōko consciously rewrote her own timeline. Returning to her fourth-grade classroom, she completed the future goals assignment she had previously left blank, accepting a reality where she never met Sakuta or Mai. This act relinquished her memories of them but ensured her survival via an unspecified donor, implied to be influenced by Mai's public film portrayal of her story. In the new timeline, Shōko recovered fully and encountered Sakuta and Mai on Shichirigahama Beach as a healthy child. Though officially strangers, fragmented memories led all three to recognize each other subconsciously. Her personality remains consistently kind and idealistic across all timelines. She voluntarily aids others experiencing Adolescence Syndrome, adopts abandoned animals, and prioritizes minimizing emotional burdens on her family. Theoretical frameworks suggest her multiple manifestations stemmed from "Adolescence Syndrome," splitting her into three entities: one stagnating in childhood, one progressing normally, and one accelerating into adulthood—though this remains conjectural. In later years, she moved to Okinawa, eventually sending Sakuta a photograph of her tanned self, confirming her ongoing recovery and new life.