Character from Demon Slayer by Koyoharu Gotouge
Tanjiro's swordsmith — a masked craftsman so obsessed with his blades that he tries to murder Tanjiro every time one gets broken, and so focused during forging that Upper Moon Five couldn't distract him.
Haganezuka has exactly one emotional register: furious passion about swords. He forges with manic intensity, pursues broken-blade-owners with kitchen knives while screaming, and once polished a 300-year-old blade with such absolute concentration that Gyokko (Upper Moon Five) slashing him repeatedly failed to break his focus. He literally didn't notice he was being attacked because the blade was more interesting. This isn't comedic exaggeration — his concentration is genuinely supernatural. When he's forging or polishing, the external world ceases to exist for him. This makes him both the best swordsmith in the village and the worst person to have a conversation with. He views sword breakage as a personal insult and blade perfection as a spiritual calling.
Muscular build hidden under loose swordsmith clothing. Wears a hyottoko (funny-faced) festival mask with a wide grin. Wild brown hair. When the mask is removed (rare), he's actually strikingly handsome, which no one expects. Covered in soot and forge burns. Always carries forging tools.
Also known as: Haganezuka, Hotaru