Hotaru Haganezuka

Hotaru Haganezuka is a swordsmith affiliated with the Demon Slaying Corps.

Appearance
Hotaru wears a sunflower-patterned robe and a large, woven hat with hanging floral wind chimes. His head is wrapped in a spotted cloth and his face is concealed by a Hyottoko mask (wooden festival mask), similar to Sakonji Urokodaki.

During the Swordsmith Village Arc, he is seen with a more muscular build compared to his initial appearance.

Unmasked, Hotaru is revealed to have long, black hair coupled with sharp eyes and distinctly-shaped thick eyebrows.

Personality
Hotaru is a rather hot-blooded individual. He seems to show very little care, if any, about anything besides the swords he creates. His passion for swords is so strong that he would be able to speak about them for long periods of time, a trait unique even among the people from the Swordsmith Village.

The same passion that gives him the enthusiasm and extreme dedication in creating swords is also the reason why he is easily enraged (usually in a comical fashion) towards swordsmen that break his creations, especially Tanjiro Kamado, no matter the circumstance.

When angry, he usually calms himself down by eating mitarashi dango or by having others pin him down (one method being tickling his sides). It is later on shown that his skills and concentration on swords is so immense that he would lose clients due to his eccentric and asocial behavior and is actually happy that Tanjiro still trusts him in making his swords. His concentration also prevents him from paying any attention to his surroundings when forging a decent blade, even when a Demon was attacking him.

Final Selection Arc
Hotaru first appears at Urokodaki's house to deliver Tanjiro's Nichirin Blade after the latter passes the Final Selection. Despite Tanjiro's frequent requests for him to enter the house, Hotaru ignores him and sits outside the door, describing the blade he forged.

After suddenly looking up at Tanjiro, he comments on his red hair and eyes, stating it was good fortune. Excited, Hotaru enters the house while remarking how Nichirin swords would change color and that his sword could turn a bright red, however, after seeing the blade turn jet black, Hotaru shows evident disappointment and gets angry at Tanjiro.

Natagumo Mountain Arc
During his fight against Lower Moon Five, Rui, Tanjiro breaks his blade and Hotaru is briefly seen in Tanjiro's thoughts as he internally apologizes to him and Urokodaki.

Functional Recovery Training Arc
After Tanjiro heals at the Butterfly Estate, he and Inosuke Hashibira greet their swordsmiths but are met with an angry Hotaru charging at Tanjiro with a knife, furious about his broken blade. After chasing him and then calming down, Hotaru and Kozo Kanamori give the swordsmen their blades.

Demon Train Arc
Hotaru appears when Tanjiro comes back from the Rengoku house, enraged over the loss of another sword and chases Tanjiro again.

Entertainment District Arc
After Tanjiro wakes up from his coma, Kiyo Terauchi shows him the fierce letters Hotaru sent after his sword got chipped.

Abilities and Powers
Being a swordsmith, Hotaru has shown to have no indication of any special abilities similar to the members of the Demon Slaying Corps. Though after Tanjiro broke his Nichirin Blade multiple times against members of the Upper and Lower Moons, he underwent special training mountains so he could forge a stronger blade for Tanjiro (albeit he wouldn't admit it).

Natural Abilities

 * Enhanced Strength: After training in the mountains, his increased strength apparently exceeded that of even Tanjiro.
 * Master Swordsmith: Hotaru is a skilled swordsmith, able to forge the Nichirin Blade and repaired it multiple times each time it broke against the Lower and Upper Moons. After Tanjiro lost another sword after impaling Akaza, Hotaru trained more to make a stronger sword. Hotaru demonstrated his professionalism and expertise when he polished and sharpened the 300-year-old blade left in Yoriichi Zeroshiki while completely ignoring the wounds he received from Gyokko.

Trivia

 * Hotaru's surname contains the kanji for "steel" (鋼), a reference to his occupation, and his first name means "firefly" (蛍).
 * He hates his first name due to how "cute" it is.
 * Hotaru's favourite food is mitarashi dango, and he goes out to buy some whenever he loses his temper.
 * Hotaru as windchimes attached to his hat because he's liked them since he was a child. Whenever he would throw a tantrum, the adults would chime to to calm him down.
 * As a child, Hotaru was so horrible to deal with that his parents had a mental breakdown and Tecchin Tecchikawahara had to raise him.

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