Louisa is a 26-year-old woman living a quiet, routine-oriented life with her close-knit family in a small English town. Following the loss of her beloved café job, financial pressure forces her to accept a care assistant position for a wealthy quadriplegic man. She possesses a highly talkative nature, deep empathy, and a bright, eccentric fashion sense, famously favoring yellow-and-black striped tights. Though she initially clashes with her new employer's bitter attitude, her refusal to be intimidated slowly begins to break down his walls.

Will is a former corporate success who was paralyzed in a severe accident two years prior to the main story. Now living as a quadriplegic in a custom annex built by his parents, he is deeply depressed, physically unkempt, and angry about his loss of independence. He deliberately attempts to frighten away his caregivers with caustic sarcasm, guarding his emotional pain and resisting any attempts to cheer him up.

Camilla is Will's mother and a local magistrate who maintains a strict, restrained demeanor. Devoutly Christian and often seen fidgeting with her crucifix necklace, she struggles to process her son's severe injury. Driven by a desperate need to protect Will, she hires Louisa in hopes that a cheerful presence will improve his outlook on life, even as she tightly controls the rules of his care.

Steven is Will's father and the overseer of the local castle in their hometown. He projects an image of wealth and stability, though his frequent absences and detached behavior hint at fractures within his marriage to Camilla. He tends to support Will's desire for autonomy and provides a less overbearing parental presence than his wife.

Nathan is Will's long-time nurse, originally from New Zealand. He handles the complex physical realities of Will's spinal cord injury with practical expertise and a calm, grounding presence. He serves as an informal mentor to Louisa, teaching her how to anticipate Will's medical needs while maintaining a professional boundary with the Traynor family.

Treena is Louisa's younger sister and a young single mother living in the crowded Clark household. Highly intelligent and ambitious, she hopes to resume her education, a choice that inadvertently places more financial pressure on Louisa. Despite occasional sisterly friction over space and money, she serves as Louisa's most trusted confidant and sounding board.

Patrick is Louisa's long-term boyfriend, a self-proclaimed entrepreneur whose life revolves around intense triathlon training. He values routine and physical fitness above all else, often prioritizing his workout schedule over quality time with Louisa. While he initially represents stability, his self-centered nature becomes increasingly apparent as Louisa steps out of her comfort zone.

Alicia is Will's ex-girlfriend from before his motorcycle accident. She attempted to support him in the immediate aftermath of his injury but was ultimately pushed away by his anger. Her visit to the annex brings painful reminders of Will's past life and forces him to confront the future he lost.

Rupert is Will's former best friend who visits the annex to announce his engagement to Alicia. His presence serves as a harsh reminder of the healthy, active peers Will left behind following his accident.

Georgina is Will's sister, who lives away from the daily realities of the annex but feels the emotional weight of her brother's choices. She frequently argues with Will, frustrated by his stubbornness and the heavy toll his depression takes on their parents.

Thomas is Louisa and Treena's nephew, currently attending university. His visits home require the family to shift their cramped sleeping arrangements, adding to the domestic pressure Louisa feels in her small hometown.