Geschlecht by German activist and author Friedrich Radszuweit, and Magnus Hirschfeld's book Geschlechtskunde, Katter became aware of diverse iterations of sexuality and gender, which informed his own sense of identity.

[4] In 1927, at age sixteen, Katter visited Magnus Hirschfeld's Institut für Sexualwissenschaft in Berlin with his mother, seeking gender affirming surgery in the form of a double mastectomy.

As described by historian Katie Sutton in her article, "Trans Rights and Cultures in the Weimar Republic," without these passes, and occasionally even with them, gender diverse individuals could be persecuted under Germany's “gross mischief” or “public nuisance” laws.

[6] In 1947, Anton Ackermann, the head of the cultural department of the SED, received a letter from Katter advocating for the commemoration of Magnus Hirschfeld and the reconstruction of the Institut für Sexualwissenschaft, which had been destroyed by the Nazi Party.

"[11] Following this letter, Katter contacted friends of Hirschfeld and individuals with cultural influence who he felt may support his endeavour including the German Jewish writers, Friedrich Wolf and Arnold Zweig.