Xavier is a 29-year-old veterinary clinic owner who projects a gruff exterior to protect himself from the emotional demands of his work and his abusive past. He secretly performs acts of deep compassion by saving healthy animals slated for euthanasia. He lives primarily for his veterinary practice and his volunteer work.

Samantha is a 28-year-old social media manager working remotely for Murkle's Mustard. She prepares for a major life change as she moves to California to help care for her mother with early-onset dementia. She possesses a witty, optimistic outlook on life and believes that people are inherently good.

Lisa is Samantha's 54-year-old mother who recently received an early-onset dementia diagnosis. Once a fashionable and accomplished CEO, she now struggles with basic functions and recognition of her own family. Her condition fundamentally alters her family dynamics as they adjust to providing her constant care.

Tristan is Samantha's younger brother. He leads a nomadic lifestyle with a sarcastic and abrasive exterior that masks his genuine love for his family. He often functions as the family's harsh truth-teller when facing difficult realities.

Jeneva is Samantha's older sister and a special education teacher. She is a single mother raising two boys following a difficult divorce. She serves as a stabilizing presence for the family while contributing to their mother's care.

Dan is Samantha's father and Lisa's primary caregiver. He faces the profound loneliness of loving a spouse who is physically present but increasingly mentally absent. He manages his wife's confusion while working full-time to support the household.

Grandma is Lisa's mother and the 77-year-old matriarch of the family. A first-generation Mexican American and former hippie, she provides stability and a home base where the family gathers. She serves as a primary daytime caregiver for Lisa before Samantha arrives.

Dr. Hank is a retired veterinarian in his eighties who formerly employed Xavier's technicians. Recently widowed, he seeks purpose by offering his services at Xavier's clinic for free. He carries a significant connection to Xavier's past.

Maggie is a veterinary technician at Xavier's clinic. She supports Xavier's rule-breaking efforts to save healthy animals and consistently checks on his personal well-being.

Tina is a veterinary technician working for Xavier. She shares in the clinic's secret rescue operations and encourages Xavier to pursue a personal life outside of work.

Pooter is a five-week-old stray kitten born with a congenital condition requiring expensive surgery. Samantha's determination to fund the kitten's operation acts as the catalyst for her meeting Xavier.

Jake from State Farm is a healthy dog whose owner requested euthanasia. Xavier secretly saved him and brought him home, giving the dog a comedic haircut to disguise his identity.

Winnie is Xavier's childhood dog. Her difficult circumstances during his youth inspired him to become a veterinarian and protect vulnerable animals.

Mike is one of Xavier's close friends. He encourages Xavier to socialize more and gently pushes him to pursue a relationship with Samantha.

Chris is part of Xavier's tight-knit group of friends in Minnesota. He supports Xavier and quickly welcomes Samantha into their social circle.

Jesse is a childhood friend of Xavier whose family once provided Xavier with a safe place to live. He remains one of Xavier's most trusted confidants.

Becca is Jesse's girlfriend. She understands Xavier's intense personality and provides him with practical encouragement before his first date with Samantha.