His best friends are  Doppio Rhum (Double Rum) and Dottor Salasso (Doctor bloodletting). Doppio Rhum was inspired by the actor Gabby Hayes in many western films of the 1930s and 1940s, and Dottor Salasso by the drunken Doc, portrayed by Thomas Mitchell in the classic western film Stagecoach (1939).
Miki is a young boy who, after carrying out a number of successful missions is promoted, in spite of his young age, to the rank of captain of rangers in Nevada. Miki has a young fiancée, Susy, the daughter of the fort commandant.