Zenitsu Agatsuma, the cowardly yet incredibly quick warrior, is one of the main characters in Kimetsu no Yaiba / Demon Slayer. The yellow-haired swordsman with the yellow and orange gradient haori is far from being weak.

To get you to love this more-than-meets-the-eye swordsman, here are the 8 most interesting things about Zenitsu Agatsuma from Demon Slayer.

1. Zenitsu’s Hair Isn’t Originally Yellow

Let us start with an easy one – something already revealed in the anime. Zenitsu, like most Japanese people, has black hair – it was in Chapter 33 and Episode 17. He dreaded fighting during his encounter with the Older Brother Spider Demon. He tried to hide and cowered above a tree. Zenitsu then recalled his training days. He was trained by a former pillar, Jigoro Kuwaijima.

Zenitsu complaining and cowering with his training. He initially had black hair.

Complaining about the supposedly harsh training, he climbed on a tree and hid. A lightning struck him from above, which turned his hair to the same yellow-orange gradient we all know.

Scientifically speaking, there has been no documented case of a lightning strike changing a person’s color. Lightning strikes can create a Lichtenburg figure to people struck by it. These are the fern-looking, lightning-style scars in a person’s body. Lightning strikes on people has also created sudden geniuses. There are reports where people have become musical geniuses after being hit by something like a billion volts.

Dare to try? Just kidding. Please don’t do anything stupid.

The moment after Zenitsu was struck by lightning. Whether the lightning had the sense to match his hair to his outfit or it was a coincidence, we don’t know.

As a fan theory, this event might actually have something to do with his unique sword fighting technique. Zenitsu often appears to fight asleep, which leaves him reliant on his natural instincts and reflex to fight. As a Thunder Breathing user, their techniques focus on channeling their increased abilities to their legs, allowing them to move incredibly fast. In his “sleeping” state, he bypasses his consciousness in decision-makings, reducing the downtime and making him remarkably faster.

2. Why Does Zenitsu Have A Sparrow?

This is one of the minor details in the series that never got a formal explanation. After the final selection, five swordsmen passed. However, only four appeared in both the anime and the manga. They are Kamado Tanjiro, Genya Shinazugawa, Kanae Kocho, and Zenitsu Agatsuma. However, in Episode 5 of the anime (Chapter 8 in the manga), a crow reports to Kagaya Ubuyashiki that five passed. The fifth one is Inosuke Hashibira, not shown in the ceremony.

Zenitsu receives a sparrow after surviving the Final Selection. He is the only one who has a sparrow while others have their crows.

While it was never explained, one of the most common reasons has something to do with the sparrow as a symbol. Sparrows are often related with peace and happiness, away from worries and fear. It is a good sign to send to someone like Zenitsu, who is always scared and anxious.

The Only Messenger Bird Who Can’t Speak

Anyway, all survivors had their Demon Slayer uniforms, the ore for their Nichirin blades, and a kasugaigarasu or a kasugai crow. These are their Taisho-era walkie-talkies. However, Zenitsu receives a sparrow instead. “Chuntaro” is the only kasugai “crow” to appear in the series without the ability to speak like humans.

While it talks in chirps, it has been shown that Tanjiro can actually understand Chuntaro. When Tanjiro saw Zenitsu begging a young woman to marry him, it was the sparrow that explained the situation to him.

Ukogi/ Chuntaro’s Past

Later, during the Taisho Secret portion at the end of Episode 15, Chuntaro talks. He reveals that his real name is Ukogi, because he loves ukogi rice.

It’s time for a Taisho Secret: My real name is Ukogi. This is because I love ukogi rice, but Zenitsu probably has not noticed it yet.

Also, in the Kimetsu no Yaiba Databook, it was revealed that Ukogi/ Chuntaro has the same story as most demon slayers. His family was killed by demons and he is the only sparrow to ever pass the Kasugai Crow tests.

3. Zenitsu’s Sword – The Rare and Unbroken

Contrary to most Nichirin Blades, Zenitsu’s blade does not just have a plain color along its length. Instead, it has a bright yellow lightning pattern running along the length of its blade. It has a yellowish hand guard or tsuba which looks like a round cross.

Zenitsu Yellow Nichirin Blade
Zenitsu draws his katana out of jealousy at Tanjiro during their stay at the Wisteria House.

Fun fact: among the three main swordsmen – Tanjiro, Inosuke, and Zenitsu – he is the only one to have never broken his sword across the entire series. Within the Demon Slayer world, the understanding that a swordsman only breaks his sword due to experience, or the lack thereof. Thus, it is a testament to Zenitsu’s skill as a swordsman. Talking about Zenitsu’s skill brings us to the next frequently asked question about him:

4. Does He Become a Pillar?

No. We have previously mentioned that after the battle with Kibutsuji Muzan, the Demon Slayer Corps was dissolved. Kiriya Ubuyashiki is now the young leader of the corps after his father, Kaguya, died. He called the remaining two Hashira: Wind Pillar Sanemi Shinazugawa and Water Pillar Giyu Tomioka. Kiriya then expressed gratitude and formally disbanded the demon slayers. The two surviving pillars expressed their gratitude to Kiriya and the Ubuyashiki family in return.

However, there are a few interesting points about Zenitsu being qualitied as a pillar.

1. Zenitsu has killed an Upper Moon Demon ALONE.

He has defeated Kaigaku, who is the new Upper Moon Six after Gyutaro. During the Infinity Fortress arc, the demon slayers split up and he found his senpai, his upperclassman and fellow Thunder Breathing disciple. In a quick battle, he defeats Kaigaku.

Zenitsu using his own technique, Thunder Breathing Seventh Form: Honoikazuchi no Kami. He finished an Upper Moon Demon, Kaigaku, with this move.

In retrospect, he is the only character shown to do so aside from Tokito Muichirou, the Mist Pillar. Muichirou defeated Gyokko, Upper Moon Five, alone. Tanjiro defeated Akaza (Upper Moon Three) with Giyuu’s help. Later, they’d all defeat Muzan with everybody alive at that point. Inosuke defeated Doma (Upper Moon Two), with Tsuyuri Kanao and Shinobu Kocho’s poison.

2. Zenitsu has done something only a pillar was able to do – create his own form.

It has been established that Zenitsu can only use the first form of Thunder Breath: Thunderclap and Flash. However, he has mastered it to the point that he has basically upgraded the skill. He can use it Six Fold, Eight Fold, and the extremely fast God Speed.

Zenitsu using the Sixfold form of the Thunder Breathing First Form: Thunderclap and Flash.

His fellow disciple turned demon, Kaigaku, can use all forms (Second to Sixth) except for the first. During their fight, Zenitsu used the Seventh Form: Honoikazuchi no Kami. It was a form he developed himself, in the hopes of fighting alongside Kaigaku. The only other Pillar shown to create his own form from an existing Breathing Style is Giyu. Giyu Tomioka, Water Pillar, created the Eleventh Form: Dead Calm.

3. He was set to become a tsuguko.

While not directly stated, it has always been mentioned that both Zenitsu and Kaigaku were meant to be joint successors to Jigoro’s position.

5. Zenitsu is Musically Talented

Just as Tanjiro has his smell and Inosuke his touch, Zenitsu has a heightened sense of hearing. Zenitsu has explained that he can use this ability to find demons because Demon bodies create a different sound compared to normal humans.

However, Zenitsu’s sensitivity to sound has also gifted him with another talent – music. During the Entertainment District Arc, the three disguised themselves as women and sent to different places to work and investigate.

Zenitsu, in his disguise as Zenko, shows his hidden talent in playing music. He can play a tune after hearing it once.

With his amazing hearing, Zenitsu reportedly has the ability to play whatever she hears one time. The women at the House she was sent in were amazed. Although Zenitsu is ugly (in his disguise), he is really good at playing the shamisen and the koto. These are traditional stringed instruments played by entertainers.

6. His Purpose for Joining the Corps

Zenitsu actually joined the Demon Slayer Corps for the same reason Tanjiro did: revenge. Despite his overwhelming cowardice, he actually loves his “grandpa.” Zenitsu and Kaigaku were the students and disciples of the former Thunder Pillar and cultivator Jigoro Kuwaijima.

Kaigaku shown in Zenitsu’s flashback, berating him and calling him harsh words.

Unfortunately, as disciples, Zenitsu only mastered the First Form while Kaigaku mastered everything except the First Form. Kaigaku first joined the Demon Slayer Corps. During a mission, Kaigaku faced the Upper Moon One, Kokushibo, and prostrated himself in order to survive. Upon learning that his first disciple turned into a demon, Jigoro Kuwaijima killed himself by committing seppuku.

In fact, when they first met again during the Infinity Fortress Arc, Zenitsu has no fear in the face of the Upper Moon Demon. He even went to trash talk his former upperclassman. “You seem thrilled to have reached the very bottom of the upper ranks through merely filling in blank positions,” Zenitsu said. He later flexed his speed by dodging the demon’s attack and slicing its neck.

While he used to respect his upperclassman, Zenitsu no longer has the same emotions towards the demon that caused the death of his master.

A small detail: after the final battle and everything returns to normal, Zenitsu wears the same haori as his late mentor. While it was not colored, the black haori with white triangles is similar to the one worn by Jigoro as he appeared in the manga. Should it be colored with the same palette, Zenitsu would have a yellow-brown haori with pale yellow/ dirty white triangles.

7. Will Zenitsu Marry Nezuko?

Yes. One of the off-putting characteristics of Zenitsu early in the series is that he always seems desperate to get married. It was how Tanjiro found him on the way to his next mission. Zenitsu was pleading a girl on the road to marry him, even crying in desperation. It was also how his mentor Jigoro found him, deep in debt because she was tricked by a woman.

Jigoro Kuwaijima saving Zenitsu from his debtors.

Zenitsu does not even appear too old to be rushing marriage. According to the Kimetsu no Yaiba databook, Zenitsu is 16 years old when he first appeared. During the course of the series, he has only one main love interest – Nezuko Kamado, Tanjiro’s younger sister. Their relationship evolves throughout, mostly marked by Zenitsu’s maturity.

Zenitsu X Nezuko Moments 1: “Give Me Back All The Blood I Shed!”

Tanjiro agreed to show Zenitsu what was in the box as gratitude for keeping it safe. Zenitsu was very scared at first, knowing that it is a demon inside it. He even ran to Inosuke for protection. However, once he saw what was in the box, he immediately fell for Nezuko. Zenitsu does not seem to mind that she is a demon. He was enraged that Tanjiro traveled with such a cute girl. After drawing his sword, Zenitsu asked Tanjiro to give back all the blood he shed protecting the box.

Zenitsu chasing the Kamado siblings after seeing how beautiful Nezuko is, despite being a demon

Zenitsu X Nezuko Moments 2: Small Talk and Respecting Girls

After the battle at Natagumo Mountain, Zenitsu, Tanjiro and Inosuke recovered at the Butterfly Mansion. They have also undergone the Rehabilitation Training under Shinobu, Kanao, and their helpers at the mansion.

As Inosuke and Tanjiro received their new swords, Zenitsu stayed in the room (because he didn’t break his sword, never will). He told stories about his day to Nezuko, who was still in her box. She responds by making muffled sounds and tapping her box. For some reason, this scene was did not make it into the anime. This short yet sweet exchange is in Chapter 51 of the manga.

Zenitsu tells Nezuko (in the box) about his day, with the demon responding by making sounds in the box.

On the other hand, there is also a pivotal moment for Zenitsu that is only in the anime. It was also a short exchange, but would mark a change in his personality. As the band leaves the Butterfly Mansion, the three assistants Sumi, Kiyo and Naho bid them farewell. Zenitsu then assumes that the three kids are heartbroken to see him leave.

Sumi, Kiyo, and Naho tell Zenitsu to be more considerate in front of women.

The three assistants then replied: “Master Zenitsu, please try to learn how to be considerate and respectful of girls.” From that point on, Zenitsu has never appeared to harass or creep out girls in the series. Case in point: Zenitsu in the Entertainment District Arc. He’s focused on the mission, even while he found himself surrounded by beautiful women.

Zenitsu X Nezuko Moments 3: I Will Protect You

During the Infinity Train Arc, the Lower Moon One Enmu has hijacked the titular train. In his awesome sleeping state, Zenitsu defends Nezuko from the demon appendages in the train. He then tells Nezuko that he will protect her, before returning to mumbling.

Zenitsu protecting Nezuko from Enmu’s appendages during the Infinity Train Arc. Note that he’s asleep at the time.

A little later, after the Swordsmith Village Arc, Nezuko has discovered that she’s resistant to sunlight, which kills all demons. Since she no longer wears her muzzle/ pacifier, she can now speak. It marks the return of the fawning Zenitsu from the early parts of the series. He promised Nezuko to always feed her sushi. Zenitsu then asked Nezuko to get married. Nezuko, however, calls him Inosuke by mistake, setting Zenitsu on a warpath. It’s a joke, of course.

As Zenitsu fawns over Nezuko in the sunlight, the female demon calls him Inosuke.

By the end of the series, the two would end up together. In modern day Tokyo, they have two descendants. They later have a 17-year-old great-great-grandson Agatsuma Yoshiteru and his older sister, 18-year-old Agatsuma Touko.

The descendants of Tanjiro, Kanao, Zenitsu, and Nezuko.

8. Zenitsu’s Name and a Small Fact

Kiyoharu Gotouge, the author of Kimetsu no Yaiba, has explained that Zenitsu’s surname, “Agatsuma,” literally translates to “my wife” in Japanese, something he has been looking for a long time. His first name, “Zen’itsu,” means “goodness.”

In an interview, Gotouge-sensei explained that in pronouncing his name, the emphasis should be on the second syllable. It is less on the “Zen” and more dragging on the “suuuu…”

Also, in the extra pages of Volume 7, it revealed that Zenitsu has an overbite. An overbite generally refers to the condition where a person’s upper rows of teeth is a bit more forward compared to the lower row.

Bonus: Zenitsu’s Voice Actor Hiro Shimono

In the Ufotable anime adaptation of Demon Slayer, Zenitsu Agatsuma is voiced by veteran Japanese VA Hiro Shimono. The 40-year-old Tokyo-based VA has been in the industry for quite some time. Our beloved Zenitsu Agatsuma shares the same voice actor with the following anime characters:

  • Dabi from My Hero Academia
  • Satoshi Mochida in the Corpse Party series
  • Shifu from D. Gray-Man
  • You Satou in Ben-To
  • Sasuke Tsubaki in Sket Dance
  • Keima Katsuragi in The World God Only Knows II
  • Lucifer/ Hanzou Urushihara in The Devil Is A Part-Timer!
  • Connie Springer in the Attack on Titan series
A collage of VA Hiro Shimono with most of the characters he voiced over the years. Thanks to u/yalu1212 for the image.