3000 Leagues in Search of Mother is about an Italian boy, Marco, and his journey in search of his mother. Italy was in a deep depression, so to support her family, Marco`s mother went to Argentina to work as a domestic (like Piccolo`s sons went to America to work in Porco Rosso). But after she wrote to her family that she was sick, her letters stopped coming. So Marco decides to go to Argentina to look for her. Marco has to travel across Argentina to find her, meeting many wonderful people, and encountering many adventures during his journey.