Hotaru wears a black yukata with sunflower-patterned haori over it and has his head wrapped in a spotted head scarf. Like the rest of the swordsmiths, his face is concealed by a Hyottoko mask (wooden festival mask) to conceal his identity. When traveling, he wears a large, woven hat with hanging floral wind chimes on top of the head scarf. When enraged at Tanjiro losing his sword for the second time, Hotaru takes off his haori and opens up his yukata to show his chest a bit more, also turning his head scarf into a headband, using it to display two knives on his head and reveal his long black-hair. During the Swordsmith Village Arc, he is seen with a more muscular build compared to his initial appearance after he had been training in the mountains.[3] In addition, a lock of his hair is exposed from his scarf. Unmasked, Hotaru's long, black hair is fully freed and is revealed to have sharp, orange-colored eyes coupled with distinctly-shaped thick eyebrows. Hotaru is a rather hot-blooded individual. He seems to show very little care, if any, about anything besides the swords he creates. And he also loves and cares for his wife, Guest, very deeply. 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 other swordsmiths. 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 who misuses his creations, especially Tanjiro Kamado, no matter the circumstance.[5] When angry, he usually calms himself down by eating mitarashi dango. Bystanders can subdue him by either pinning him down or tickling his sides, as demonstrated by Kozo Kanamori, after which he will fall limp. As Hotaru is socially inept in dealing with people, he is still unmarried. His intense and asocial behavior also causes other swordsmen to hate him and he lost a lot of clients because of this. Although he won't be honest about it, he is actually happy that Tanjiro still trusts him in making his swords.[7] His concentration on sword-making is so immense that it prevents him from paying any attention to his surroundings when forging a blade, even when a demon is attacking him and inflicting severe injuries on him.[8] When the process of forging or refining is interrupted by taking the sword away, he feels the need to restart the whole process from scratch again. As a perfectionist, any small scratch on a blade that is irremovable hurts him immensely.[9] Despite his notorious asocial and volatile personality, he shows a more surprisingly pacified and rational side when a woman that Kozo, Tecchin, and Kotetsu attempted to matchmake with Hotaru degrades swords as antiquated and barbaric. Hotaru points out the perseverance that Demon Slayers display and the daily risks they face and proclaims that he is proud to forge swords for them, and frankly turns her down. This shows that despite his unruly and borderline insubordinate personality, Hotaru does have a deep respect for the Demon Slayers. Plus, he has a wife who respects and actually admires his sword making skills. He is 37 years old. He is also 6’6. Favorite food is mitarashi dango.