Herr Rossi is a Milanese chimney sweep master who acquires Romeo upon the boy's arrival in the city. He lives under the financial and domestic control of his wife, Edda, whose domineering presence shapes the household atmosphere. Rossi battles alcoholism, frequently diverting household funds to wine, fueling neglectful behavior towards Romeo. His initial treatment of the boy is unfair and indifferent, often swayed by Edda and their son Anzelmo's mistrust.

Rossi instructs Romeo in chimney sweeping techniques and secures work assignments. Despite his flaws, he shows occasional kindness, especially when free from his wife's immediate influence. A profound shift occurs when Rossi witnesses Romeo's integrity and courage, prompting him to confront his own role in the boy's suffering. This sparks gradual growth toward greater empathy and fairness in his dealings with Romeo.

Rossi also acts as guardian to his adoptive daughter, Angeletta, taken in at Countess Isabella's request. Confined indoors due to a heart condition, Rossi indirectly nurtures Angeletta's emotional needs. He eventually facilitates her reunion with her estranged grandmother, Countess Isabella, recognizing this connection as vital to Angeletta's well-being.

By the series' end, Rossi acknowledges Romeo's positive influence on their household, particularly regarding Angeletta. His relationship with Edda improves as he asserts more autonomy in decisions, fostering mutual respect. Rossi honors the terms of Romeo's contract, permitting his departure upon fulfillment, demonstrating a lasting change in how he treats those under his care.