Viewers of the popular anime Demon Slayer noticed very quickly that Tanjiro Kamado wears unique earrings that help to identify him. Especially since he is one of the very few characters in the anime to wear earrings at all, only a few of the Hashira are depicted with such adornments. But only extremely keen-eyed viewers would have noticed the impact that seeing those earrings had on other characters in the show. These Hanafuda earrings have a cultural significance both within and without the realm of Demon Slayer. This cultural significance stands as proof that the animators/character designers poured their passion into every single detail of this beloved show.
In the anime Tanjiro and his younger sister Nezuko’s life is shattered when their family is slaughtered by a demon and she is turned into one herself. Tanjiro immediately reacts contrary to the nature of the world and defends his sister’s life against the first demon slayer that they encounter. He is then compelled by that man to pursue a career in the Demon Slayer Corps in order to safeguard human life. Tanjiro’s quest then gains a grander scale when he decides to make it his mission to take on the king of demons Muzan Kibutsuji, after discovering that that might be the only way to save his sister and return her to humanity.
In the Real World
Hanafuda is a Japanese word that can be translated to “flower cards” and describes a style of playing card that are smaller than traditional western playing cards. They are colorfully decorated and often have a certain amount of symmetry to them, though this is not a requirement. The design on Tanjiro’s Hanafuda earrings is similar to that of the playing cards though not exactly identical.
It might be more accurate to say that they were inspired by these real-world cards. It has also been speculated that the difference in the earrings from the cards might have been to make them resemble the Japanese motif of the rising sun. This has two-pronged support, both with the cultural significance of anime and the rising sun in Japan, and with the significance of the sun in the anime.
This similarity to the rising sun in Japan has sparked controversy on its own and resulted in altered versions of the earrings being distributed in other Asian countries. This altered design depicts four horizontal lines below the red circle instead of streaming out of it. This was designed to avoid connections with the Japanese flag specifically associated with WWII war crimes.
In the Anime
These earrings that Tanjiro wears have an extensive history. They were originally worn by the legendary Demon Slayer Yoriichi Tsugikuni, the originator of the breathing styles that so pervade the Corps. Tanjiro’s ancestor was a good friend of Yoriichi and arguably was one of his only true friends. Therefore Yoriichi gave the earrings as a gift, and since then they have been passed down the generations until they reached Tanjiro. More importantly, Yoriichi also originated the ultimate breathing technique, sun breathing, from which all other techniques are derived.
When the Demon King first interacts with Tanjiro his first impression is that of fear, especially when he notices the Hanafuda earrings. This is due to the fact that the last true danger to him came from this original sun breather. Muzan had previously believed that he had slaughtered all who had known of this ultimate technique and viewed the earrings as a sign that there was still yet a sun breather. Unfortunately for him, this did end up being true, although not till much later. This fear that was instilled in Kibutsuji was so deep that in the very next episode he commanded his subjects to bring him the head of the Slayer who wears the Hanafuda earrings.
This fear turns out to be true despite even Tanjiro being unaware. Just as his father passed along the earrings to his son he also passed along a traditional family dance that held the key to sun breathing. The earrings, despite having lost their meaning to mortals, did in fact represent the bearer's understanding of those secret arts that Muzan had so aggressively tried to eradicate.
In Summary
The Hanafuda earrings worn by Tanjiro in Demon Slayer have meanings both within their world and in the real world. The real-world meanings are both beautiful and controversial in their implications and have resulted in modifications to the original design. The in-world meanings of the earrings however have managed to maintain their authenticity even when viewers and characters alike had no idea. They represent power and strength and hidden skills. They inspire fear in powerful demons, and viewers can recognize the beauty that was inspired by the real-life playing cards. It is rare that so much meaning is wrapped up into such a small part of an anime, but when it is pulled off as well as Demon Slayer managed to do so it is truly a testament to the writer's skill and attention to detail.