Demon Slayer is a shonen “monster hunter” anime in a roughly similar vein as the gory Chainsaw Man and the wacky Fire Force, where well-armed, specially-trained humans fight monsters to protect humanity. The demon slayers may have Nichirin swords and specialized breathing techniques, but they’re still at a huge disadvantage. No one complains about this more than Zenitsu Agatsuma.
It’s true that Zenitsu has a cowardly streak and complains often, but there’s more to his character than that. Annoying habits aside, Zenitsu is an ideal sidekick and supporter for highly motivated fighters like Tanjiro Kamado. Fans might even say Zenitsu was born to be Tanjiro’s supporter and friend, given his humility and lack of ambition. This could also set a good precedent for all demon slayers.
Why Zenitsu Is Comfortable Being Tanjiro’s Sidekick
Many shonen heroes have unofficial sidekicks — usually, a good friend who has personal reasons to support the hero. Examples are endless, from Krillin fighting alongside Son Goku in early Dragon Ball stories to Uryu Ishida supporting Ichigo in Bleach, among others. Now Zenitsu is the Krillin or Uryu of Demon Slayer, and he seems to like it. Some supporting characters are too proud to play second fiddle to the hero, such as Katsuki Bakugo, but Zenitsu is no Bakugo. Unlike both Tanjiro and Bakugo, Zenitsu lacks any serious ambitions, and he has no major goal aside from sheer survival — a defensive and open-ended priority to have. Since Zenitsu isn’t striving toward anything in particular, his personal quest is aimless and he has little to prove. He therefore can and should follow a more purpose-driven hero like Tanjiro and help the latter accomplish his goals.
Zenitsu admires and respects Tanjiro’s noble goals, and he also looks up to Tanjiro as a brave, proactive fighter who gets things done. All this means Zenitsu is, from both a personal and storytelling angle, an ideal sidekick for Tanjiro. Zenitsu doesn’t resent being Tanjiro’s #2, and he gains far more than he loses by signing up as Tanjiro’s unofficial but loyal sidekick. Alone, Zenitsu is vulnerable and has nothing to strive toward, but Tanjiro can offer companionship, protection and inspiration — all things that Zenitsu urgently needs. In return, Tanjiro has Zenitsu watching his back and fighting demons with a different style, thunder breathing, in case water breathing won’t cut it. As a bonus, Zenitsu dotes on the lovely Nezuko Kamado and enjoys spending time with her, which is only possible if Zenitsu stays in Tanjiro’s team.
The Benefits of a Demon Slayer Battle Buddy System
On a personal level, Zenitsu and Tanjiro benefit greatly from their partnership as fellow demon slayers and shonen heroes — and for the story’s own sake, it’s good to have a small hero squad built on mutual friendship and respect. Finally, for in-universe reasons, it’s a good idea for more demon slayers to do what Tanjiro, Zenitsu and Inosuke are doing. The life of a demon slayer is brutal, violent and short, based on the youthful age of the average Hashira, so demon slayers need all the help they can get. Demon slayers, therefore, need a more cohesive battle buddy system and, on a similar note, perhaps a master/apprentice system as well. No slayer should go out there alone when fighting demons.
In real life, soldiers benefit enormously from official battle buddy systems in many ways. These partners may look after each other’s mental well-being in the face of stress and hardship in military life, and they can also boost each other’s leadership skills, improve morale and promote cooperative problem-solving. Even independently strong and confident slayers like Tanjiro and Inosuke need support sometimes, and humble friends like Zenitsu can provide that help. There might be personality conflicts if two Bakugo-like slayers were assigned as partners, but if cooperative, selfless demon slayers like Zenitsu were assigned as the partners of stronger slayers, everyone could reap the benefits.
This could vastly decrease casualties on the job and boost morale, and the slayers could watch each other’s backs. Even the most elite real-world soldiers or special operatives need friends, and that goes double for demon slayers, who face superhuman opponents. Given the high mortality rate of demon slayers, Hashira or not, the demon slayer corps is long overdue to implement such a system, and humble sidekick types like Zenitsu Agatsuma are prime examples of how that system could work. Complaints and comedy aside, every slayer needs their own Zenitsu to support them with their words and blade alike.