See To hide the table of contents
Known for his loudness and antics, Demon Slayer’s Zenitsu Agatsuma emerges as the weak link in his trio of friends. He lacks Tanjiro’s ambition to keep fighting and doesn’t possess the same drive that Inosuke does. Zenitsu is quick to panic, and if it doesn’t involve Nezuko, he’ll run away rather than fight. His less amiable qualities don’t make him seem fit to be a demon slayer, especially compared to some older members.
Despite his personality, Zenitsu has strong skills and unique abilities that only he can use. Had the Demon Slayer Army not disbanded by the end of the series, Zenitsu could have become the next Thunder Hashira.
Zenitsu’s mentor was a former Hashira
One of the ways to become a Hashira in Demon Slayer is to be a person’s tsugoku and train under them. Kanao was Shinobu’s tsugoku, while initially Senjuro was his brother Kyojuro’s tsugoku. Zenitsu trained under former Thunder Hashira, Jigoro Kuwajima. Under Jigoro’s strict training, Zenitsu only mastered the first form of Thunder Breathing. Although he often tried to run away from Jigoro, he greatly respected his mentor and considered him a parental figure.
A Hashira generally seeks a successor to take their place if they die in battle or retire. After Jigoro’s death, Zenitsu could have taken over the role of Thunder Hashira. However, he felt extremely guilty that his mentor committed seppuku because one of his students turned into a demon, and he instead focused on training to become stronger and avenge his master.
Zenitsu defeated an Upper Moon by himself
The second way to become a Hashira is to kill 50 demons or defeat one of the Twelve Kizuki as a kinoe ranked killer. Tanjiro and his friends managed to kill several of the Twelve Moons throughout Demon Slayer. Giyu killed the lower fifth moon, Rui, all by himself. Tanjiro and his friends managed to defeat Lower Moon One, Enmu, with Rengoku’s help. Inosuke and Zenitsu beheaded Daki, while Tengen Uzui and Tanjiro defeated Gyutaro.
Only two individuals in the series have defeated a higher-ranking demon on the Moon by themselves. Muichiro defeated Gyokko, the demon of Upper Moon 5, all by himself during the “Blacksmith Village” arc. Zenitsu is the only other person to have achieved this feat and defeated the Upper Moon Six’s new demon, Kaigaku.
Zenitsu created an original form within Thunder Breathing.
Although creating an original form is not a trait unique to Hashira, it is an extremely difficult feat. Only two known individuals in Demon Slayer have created a new form in a breathing technique that many people already use. Water Hashira Giyu Tomioka created the eleventh form of the Water Breathing Technique, known as Dead Calm. Zenitsu is the only non-Hashira known to have developed an additional form of breathing. While training with Jigoro, Zenitsu could only master the first form of Thunder Breathing, while Jigoro’s other student Kaigaku could use all but the first form. Afterwards, Kaigaku despised Zenitsu and belittled him for his lack of strength.
During his fight against Kaigaku, Zenitsu created the Seventh Form of Thunder Breath, known as the Blazing Thunder God. Kaigaku curses Jigoro for favoring Zenitsu and teaching him a secret technique, but Zenitsu corrects his comrade and informs him that the Seventh Form is his creation – their master does not do favoritism. This fact stunned Kaigaku and infuriated him as he always considered Zenitsu to be weaker than him.
Though considered a coward, Zenitsu’s speed, determination, and skill give him strengths of his own. His training with Jigoro did more than help him in the art of thunder breathing. His master groomed him to take over and become the next Thunder Hashira of the Demon Slayer Army.