The Schöneberg cluster
Most of the gay shops in Berlin are concentrated around Nollendorfplatz in Schöneberg. The area has been a gay neighbourhood for over a century and the shops reflect that history: there is a genuine bookshop, leather stores that have been trading for decades, and sex shops that do not try to hide what they are.
Prinz Eisenherz on Lietzenburger Strasse is the oldest gay bookshop in Germany. It opened in 1978 and is still running. The stock covers fiction, politics, history, and a solid selection of LGBTQ+ German-language titles that are difficult to find elsewhere. Worth going in even if you do not buy anything.
Leather and fetish
Schöneberg has a cluster of leather shops that serve the city's active leather scene. Some are small and specialist; others stock a broader range including harnesses, boots, and gear from European manufacturers. Berlin's leather scene is substantial enough that the shops are well-stocked and competitively priced compared to the same items in other cities.
Sex shops
There are several sex shops in the Nollendorfplatz area that are open about what they sell and run professionally. They carry toys, poppers (legal in Germany), underwear, and accessories. Some are attached to cinemas. Nothing here requires any particular explanation — Berlin is a liberal city and the shops operate accordingly.
The shops
4 Hunks (at Molotow/Blackwhite), BLACKSTYLE, Bodysphere Men Concept Store, BOXER Berlin, Boyz 'R' Us, Butcherei Lindinger, City Men Shop, CloneZone Berlin, Connection Shop, DarkZone
Opening hours in Schöneberg shops are typically Monday to Saturday, 11am–8pm or later. Sunday is more variable. Some of the sex shops stay open until midnight. Berlin's general attitude toward this kind of retail is relaxed, and none of these places feel like they are hiding from the street.
For the broader Berlin picture: Gay Berlin Guide.