Hans Harald "Hasse" Zetterström was born 23 May 1877 in Stockholm, Sweden to father August Zetterström and mother Elisabet Zetterström (née Carlberg). Hasse was a prominent author, columnist and editor. He died 1 June 1946.
Hasse was noted for his use of many writing pseudonyms. At the age of 20 he began working on the magazine Figaro and in 1897 started working at newspaper Söndags nisse working in a variety of roles until becoming the editor of Söndags Nisse-Strix in 1924. As editor he commissioned the creation of Grönköpings Veckoblad, a magazine detailing the fictional Swedish town of Grönköping. Hasse also began contributing a regular column in 1931 to major national Swedish newspaper Svenska Dagbladet.
Hasse married Anna Ahlberg in 1901 and became a father to Erik Zetterström(1904-1997) and Sven Zetterström(1902-1973). Erik became a notable journalist and columnist for Svenska Dagbladet under the pseudonym of Kar de Mumma whilst Sven was a screenwriter and journalist.