Shôko Makinohara exists across multiple timelines and physical forms, profoundly shaped by a severe heart condition from birth. Frequent hospitalizations starting in elementary school defined her early life. At age ten, during a class assignment to document future goals, her illness rendered her unable to conceive or write any aspirations, symbolizing resignation to an uncertain fate. Manifesting in three distinct forms due to Adolescence Syndrome—a phenomenon tied to emotional stress—her youngest incarnation appears as a shy, cat-loving middle school student aged 13-15, standing 4'11" (150 cm). She first encounters Sakuta Azusagawa and Mai Sakurajima while sheltering a stray cat from rain, leading to the cat's adoption and her subsequent visits to their home, frequently interrupted by hospitalizations for her declining health. An older manifestation, aged 17-19 and approximately 5'2"-5'3" (158-160 cm), initially met Sakuta years earlier on Shichirigahama Beach during his middle school turmoil. She imparted a life-defining philosophy: that existence centers on cultivating kindness, striving daily to become gentler. This ideal fundamentally shaped Sakuta's outlook. Reappearing during his grief over his sister Kaede's memory loss, she offers solace and practical care, later residing temporarily with Sakuta and Mai. She reveals her heart disease and theorizes she may be a projection of her younger self's desire to reach adulthood, bearing a surgical scar between her breasts from a future heart transplant. A third version, "Shoko-san" from an alternate future, receives a heart transplant from Mai Sakurajima after Mai's sacrificial death to save Sakuta from a fatal accident. She discloses to Sakuta that his heart was originally destined for her transplant in another timeline, explaining his recurring chest scars as temporal paradoxes when multiple versions coexist. Enabling Sakuta's time travel to prevent Mai's death, this act erases her existence and ensures the younger Shoko's death from untreated heart disease. Confronting this outcome, the younger Shoko—aware of the tragedies through residual memories—rewrites reality. She completes her previously blank fourth-grade future goals sheet, expressing aspirations to live fully. This creates a new timeline where she never meets Sakuta or Mai, sparing them sorrow but sacrificing shared memories. Her heart condition is successfully treated in this revised future, likely due to heightened organ donor awareness indirectly spurred by Mai's film role mirroring her story. Years later, a healthy Shoko reunites with Sakuta and Mai at Shichirigahama Beach, fragmented memories enabling mutual recognition. Her personality consistently emphasizes compassion, selflessness, and quiet resilience across all incarnations, whether comforting Sakuta, advocating kindness, or sacrificing for others' happiness. Her narrative concludes with a hopeful, ordinary life in Okinawa, symbolizing peace after temporal and physical struggles.