Hinata Kawamoto is the middle daughter of the three Kawamoto sisters and a central figure in the story. She is introduced as a middle school student who, despite the early loss of her mother and grandmother and the absence of her father, maintains a resilient and caring presence within her family. Her father, a gambler who abandoned the family, makes an unannounced return at one point, a visit that highlights Hinata’s deep-seated anger and her struggle to reconcile her feelings, as she bluntly confronts him while her sisters react differently.

In terms of personality, Hinata is defined by her direct and honest expression of her emotions; she laughs openly, cries freely, and approaches life with a fierce bravery that inspires those around her. This is most profoundly demonstrated during a severe bullying arc at her middle school. When a close friend becomes the target of relentless harassment, Hinata is the only one who steadfastly refuses to look away, standing by her friend’s side even as others divert their gaze to avoid becoming victims themselves. After her bullied friend transfers to another school, Hinata becomes the next target. Despite her fear and the painful loneliness of being ostracized, she remains unyielding, famously declaring through tears that she will never regret her actions because she knows she was not wrong. This moral fortitude serves as a major turning point for Rei Kiriyama, the series' protagonist, as her courage directly confronts his own unhealed wounds from a past marked by isolation and emotional numbness.

Hinata’s role in the narrative is multifaceted. She is a crucial source of warmth and normalcy for Rei, whom she affectionately calls Rei-chan. Her family’s home becomes a sanctuary for him, and her unwavering spirit helps pull him from the depths of his depression. Beyond her emotional support, her personal journey forms a core part of the story’s second season, which focuses heavily on her fight against the injustice of the bullying system and the failure of the adults around her to act. Her key relationships include her sisters, the motherly Akari and the young Momo, as well as her grandfather, for whose traditional Japanese confectionery shop she harbors a deep passion. She dreams of becoming a wagashi artisan and creating her own sweets, a creative drive that contrasts with but also complements Rei’s world of shogi. Later in the series, she enters the same high school as Rei, cuts her signature twin-tails into a bob, and eventually begins a romantic relationship with him. Her notable abilities lie not in physical prowess but in her profound emotional strength, her loyalty, and her practical skills, such as cooking and designing new sweets. She is, as her name suggesting a sunny place implies, a source of light and warmth for everyone in her life.