Hotaru Haganezuka is a skilled swordsmith in the anime series Kimetsu no Yaiba (Demon Slayer). He is responsible for forging and maintaining the Nichirin Blades used by Demon Slayers. Known for his eccentric personality and intense dedication to his craft, Haganezuka often becomes fixated on perfecting his swords. He is infamous for his short temper, especially when his blades are damaged, but deeply cares about his work and the success of the Demon Slayers who wield his creations.