Josephine "Jo" Bhaer, originally Josephine March, is a central figure in an anime adaptation depicting her later life. Her background stems from a classic literary series, where she grew up as the second oldest of four sisters in Concord, Massachusetts. In her youth, she embraced a tomboyish and independent spirit, frequently challenging the era's traditional gender roles. Possessing literary ambitions and a quick temper, she consciously worked to control this aspect of her personality. Financial strain during the American Civil War led her to sell her hair to fund her mother's journey to care for her ill father.

Maturing, she declined a marriage proposal from her childhood friend and neighbor, Theodore "Laurie" Laurence, choosing to maintain their bond as siblings. She relocated to New York City, working as a governess and forming a significant friendship with German professor Friedrich Bhaer, whom she married. Following her great-aunt's death, she inherited the Plumfield estate.

Approximately ten years after her marriage, she and Professor Bhaer established Plumfield as a coeducational school. The institution served their biological sons alongside nephews, nieces, and orphaned children. Her educational philosophy emphasized experiential learning, integrating play, music, and outdoor activities into the curriculum alongside academic studies. Rivers, fields, and forests became extensions of the classroom under her guidance.

She demonstrated particular skill in mentoring students facing personal challenges, including Annie "Nan" Harding and the streetwise adolescent Dan Kean. Her approach balanced patience with firm boundaries, offering individualized support while maintaining clear expectations. She guided students through various adventures and difficulties, addressing issues from interpersonal conflicts to serious incidents like a school fire.

Her relationship with her sisters continued into adulthood, marked by regular family gatherings at Plumfield. Alongside her educational responsibilities, she maintained her literary career, achieving notable success as an author. This dual vocation reflected her lifelong dedication to both creative expression and nurturing others.

Her character development culminated in her role as educator and matriarch, applying lessons from her own unconventional upbringing to create a progressive learning environment. She consistently advocated for the value of education, compassion, and personal growth.