Demon Slayer: Zenitsu Agatsuma had incredible character development, and here’s why 

Zenitsu beheading a demon as seen in anime
Zenitsu beheading a demon as seen in anime (Image credit: Ufotable)

Demon Slayer: Kimetsu no Yaiba is an animanga series that typically centers around Tanjiro Kamado and his sister, Nezuko. However, they aren’t the only protagonists. Among the core characters, Zenitsu Agatsuma stands out as one of the two tritagonists. Introduced as a coward and an overly dramatic sidekick, no one even expected him to be a powerful character. But throughout the story, his journey is inspiring because, against all odds, Zenitsu has a great character development arc in all of Demon Slayer.

Initially, many fans disliked his character because of his constant whining and seeking protection. He appeared to be very insecure about his powers, but at the same time was delusional by always claiming that he would die in any active mission he took part in. To add on about his character, which did not help his case in gaining popularity, he was desperate to marry a girl before dying.

But what most of them failed to see is, beneath all of these traits of his that were off-putting was a boy who had incredible potential to grow. Also, Zenitsu’s fear in the Demon Slayer world was valid because death was lurking around every corner. One could be an innocent civilian or a Demon Hunter; one wrong move and they would meet their end.

Zenitsu and Tanjiro as seen in the Demon Slayer anime (Image credit: Ufotable)
Zenitsu and Tanjiro as seen in the Demon Slayer anime (Image credit: Ufotable)

His fears made him the most human among the trio. Where he lacked the iron resolve of Tanjiro or the beastly confidence of Inosuke, Zenitsu showed the meaning of being vulnerable. What makes his character development arc believable is how his story began. The transformation from being a coward to overcoming his fears was distinctly visible. His introduction was the foundation for him to build his courage eventually.

One of the most defining traits about him in Demon Slayer is how he mysteriously transforms when he is either asleep or unconscious. During a battle, if Zenitsu loses his consciousness for any reason, the part of his mind that controls fear shuts off. He can show his skills as he wields Thunder Breathing, First Form: Thunderclap and Flash. This attack is so fast that the opponent does not even realize they have been cut.

The contrast between his character when he is awake and during his unconscious state is highly fascinating. It proves that somewhere, Zenitsu has had untapped potential all along, and he just needs to move past being afraid. Suddenly, he is not someone who is just there for comic relief. Koyoharu Gotouge made sure to give enough hints that Zenitsu's true strength was buried under layers of insecurity and fear.

During the final arc in Demon Slayer, Zenitsu finally fights against his opponents while competently maintaining his consciousness. He never ran, cried, or begged for being left alone. Rather, he truly shone at that moment and also became one of the few prodigies who invented their own breathing techniques.

Also, his fears did not vanish in this; he learned how to function past it. Zenitsu has an incredible character development because he proved in that instant that it’s okay to be scared as long as one does not run away from tough situations.

Importance of Zenitsu’s Backstory in Demon Slayer

Zentisu, after using his Thunderclap and Flash as seen in the Demon Slayer anime (Image credit: Ufotable)
Zentisu, after using his Thunderclap and Flash as seen in the Demon Slayer anime (Image credit: Ufotable)

To fully understand and appreciate Zenitsu’s character development, viewers should understand where he comes from. His parents were never in the story, and he grew up with no one to guide him in the rights and the wrongs. He had to navigate life by himself. Interestingly, he was also drowning in debt after being duped by a girl who claimed to love him and ran away with his money. These experiences mentally and emotionally affected him and were the main reason for his self-doubt and fears.

His life changed when he met his mentor, Jigoro Kuwajima, the former Thunder Hashira. He was the first person who treated Zenitsu with utmost patience and care. This had never happened before, and Jigoro saw some potential in him and started training Zenitsu. Even after failing multiple times, his mentor never gave up on him. This was the reason that Zenitsu wanted to fight, as he wanted to honor the only person who believed in him when no one cared about his existence.


In conclusion, Zenitsu Agatsuma's character development was not linear. When others learned multiple types of breathing techniques, Zenitsu only mastered one, the Thunderclap and Flash. He is proof that someone does not have to be a master in everything. Finally, his complete character arc is incredible because it is highly inspiring to witness someone who was nobody become a fan favorite. And when he created his unique breathing technique, Zenitsu became the hallmark of a true master and became one of the fastest characters to be alive in Demon Slayer.

Edited by Ishita Banerjee