Monica Gabriel is a 10-year-old photographer running a mobile photography business from her wagon in the futuristic city of Judoh. She works to support herself, her unemployed mother Christina Gabriel, and her donkey Parsley. Christina is a degenerate alcoholic who sleeps off hangovers inside the wagon during the day, leaving Monica as the household's primary provider.

Her business faces financial hardship partly because she champions traditional film-based photography, an obsolete medium in her era. Despite this struggle, her work has granted her extensive knowledge of Judoh's underground activities, business trends, and criminal movements. She leverages this knowledge as an information broker for Special Services investigator Daisuke Aurora, trading crucial tips and intelligence for payment.

Monica's difficult home life forces her into maturity beyond her years, fostering a pragmatic and sometimes cynical worldview with a strong, almost fetishistic focus on financial stability. She exhibits keen perceptiveness regarding danger, identifying threats in her mother's romantic relationships before others notice. Daisuke acts as a surrogate older brother, intervening to protect her family when necessary; he once attempted to formally adopt Monica to remove her from neglect, but Christina refused.

Beyond information brokering, Monica occasionally assists Daisuke directly in investigations or recovering lost items. Her donkey Parsley provides companionship, responding to human conversation in her challenging life.