Mr. Johnson appears during Anne Shirley's residence with the Thomas family in Marysville. Initially known locally as the "Egg Man" due to his occupation selling eggs, his actual name is revealed through his interactions with Anne.

He lives in relative isolation, maintaining a reclusive lifestyle that results in a gruff and reserved exterior. This demeanor causes most townspeople to perceive him as aloof. His background includes previous employment as a schoolteacher, though the circumstances for his career change remain unspecified.

His relationship with Anne develops when she becomes a regular customer, tasked with buying eggs for the Thomas household. During these visits, he begins teaching her five new vocabulary words weekly. This educational routine significantly expands Anne's language skills and becomes a consistent element of their interactions, revealing a persistent connection to his teaching background. He demonstrates particular interest in her intellectual growth, occasionally providing books beyond their vocabulary lessons, including one significant gift of a dictionary. His commitment to her education persists even during interruptions in her formal schooling.

His character development includes forming a relationship with Miss Henderson, the local schoolteacher. Their initial interactions show mutual hesitation, but they gradually develop a rapport centered on shared concern for Anne's wellbeing and education. Their eventual engagement becomes a documented event.

Following Mr. Thomas's death in 1874, he and Miss Henderson visit Anne to say goodbye before relocating to Bolingbroke. During this farewell, they inform her of their engagement and respective career moves—Miss Henderson to attend teacher training and Mr. Johnson to teach at the high school in Bolingbroke. This departure marks his final appearance.