Lemonade is a resilient ten-year-old girl with red curly hair and green eyes. Grieving the recent loss of her mother, she struggles to adjust to her new rustic life in Willow Creek, missing the comforts of San Francisco. She initially acts closed-off and critical of the town's obsession with Bigfoot. As she settles in, her natural curiosity and energetic spirit begin to emerge through local investigative work.

Tobin is an outspoken ten-year-old boy who runs Bigfoot Detectives Inc. out of a local garage. Intensely dedicated to cryptozoology, he wears a signature safari hat and keeps detailed logs of sightings around town. He fiercely defends the existence of Bigfoot against skeptics, holding onto hope regarding the creature just as he holds onto hope for his missing father.

Charlie is a former doctor who now runs a Bigfoot souvenir shop in Willow Creek. He takes in his granddaughter after a period of estrangement from his late daughter. He initially appears awkward and introverted, struggling to communicate his feelings verbally. Beneath his quiet exterior, he actively works to build a supportive home and quietly demonstrates his affection through small acts of care.

Mrs. Dickerson is an elderly widow residing in Willow Creek who frequently contacts Tobin's agency with unverified Bigfoot sightings. Having taught Lemonade's mother in elementary school, she provides Lemonade with comforting stories about the past. She acts as a wise maternal presence in the community, offering guidance and freshly baked cookies to neighborhood children.

Debbie is Tobin's mother and a hardworking nurse. Because she works long hours, she relies on Charlie to keep an eye on her son. She attended high school with Lemonade's mother, giving her deep empathy for the young girl's loss. She maintains unwavering optimism that her husband will eventually return from the Vietnam War.

Scotty is Debbie's husband and Tobin's father. He was drafted into the Vietnam War and disappeared while en route home. Though physically absent at the story's start, his missing status casts a long shadow over his family and profoundly shapes Tobin's persistent hope for miracles.

Elizabeth is Lemonade's recently deceased mother who grew up in Willow Creek before moving to San Francisco to become a veterinarian. Known for her adventurous personality and optimism, she named her daughter Lemonade to instill those same qualities.

Lester Harold is a local rancher who experiences disturbances on his property. He becomes a key client for Bigfoot Detectives Inc. when he reports being stared at and pelted with rocks by mysterious creatures near his woods.

Miss Cotton is a schoolteacher in San Francisco. She shares a warm smile similar to Elizabeth's, making her a comforting figure to Lemonade, who hopes to return to the city to live under her care.

Eliza is a classmate of Tobin and Lemonade. She reports seeing a strange creature coming out of the woods during a game of kick the can, prompting an investigation and leading to a new friendship.