From the Super Mario Wiki
The Bombenladen (bomb shop in English) is a small shop in an unknown location run by Wario, appearing in the Club Nintendo comic "Warios Weihnachtsmärchen". While Wario is the boss and has never actually been seen working there, Bomberman is the salesclerk. The shop provides bombs of all kinds, two known examples are the "marzipan bomb" and the "surprise bomb." Characters who have bought bombs in the shop include Bowser, a Kremling, and Kid Klown.