Rei Aragaki, a fourth-grade student, is the daughter of Jotaro Aragaki, a professional gymnast, and the late Tomoyo Aragaki, a former actress who passed away during Rei’s early childhood. Her salmon-pink hair, initially cut in a bob, lengthens to her shoulders by the epilogue’s two-year time jump, complementing her warm brown eyes. She frequently dons practical blue overalls layered over a shirt and carries a vibrant red backpack to school.

Determined to ease her father’s burdens after her mother’s death, Rei shoulders household chores like cooking and cleaning, masking her own challenges—including schoolyard teasing linked to Jotaro’s celebrity—to protect him from additional stress. Her grandmother Mari provides solace by gifting Big Bird, a talkative South American parrot who becomes Rei’s steadfast confidant.

Rei fiercely supports her father’s gymnastics career, cheering him through professional setbacks while suppressing her grief to embody the cheerful resilience she associates with her mother’s memory. Her dynamic with Leonardo, a self-styled ninja and family ally, unveils a mischievous streak; their banter-filled exchanges and shared movie marathons lead Leo to affectionately dub her “Rachel.”

A pivotal friendship emerges with Kitty Zhang, a Chinese gymnast and admirer of Tomoyo, who inspires Rei to voice her dormant dream of acting. This connection sparks Rei’s shift from prioritizing Jotaro’s well-being to confronting her own ambitions. Her journey traces a path from self-sacrifice to tentative self-expression, balancing familial loyalty with emerging individuality.

The epilogue captures Rei at twelve, her bonds with Leo intact and her resolve strengthened. Her ongoing evolution—marked by quiet independence and sustained connections—reflects themes of resilience, duty, and the slow unfurling of personal aspirations against life’s adversities.