According to Zenitsu, Jigoro never gave up on him to make him stronger and a better swordsman. He took care of Zenitsu like he was his grandson, he saved Zenitsu many times and he has shown unlimited patience at training the boy despite his cowardless and laziness.
But perhaps only to my surprise, Gramps—Jigoro Kuwajima—is not Zenitsu's grandfather. He rescued Zenitsu after taking compassion on the boy, who was about to come under servitude due to debt. Kuwajima took him in, fed him, trained him, encouraged him, and helped him become far more than he was destined to be.
The previous generation of hashira (Urokodaki , Rengoku's dad, Zenitsu's Grandpa) were the strongest hashira generation. They all retired in a field where most die young.
He committed seppuku when his former protégé Kaigaku defected to gain the powers of a demon, According to Zenitsu, his death proved to be slow and agonizing since no one could cut off his head while he bled out.
The name of Zenitsu's master or sensei is Jigoro Kuwajima.
But Zenitsu is not just powerful in his unconscious state. His real power shows when he is aware and awake, he was able to outmatch the new upper rank six demon, Kaigaku. At this point Zenitsu has manifested his speed and power, and he was also able to keep up with the Demon King, Muzan, even when weakened.
After the deaths of Daki and Gyutaro, Kaigaku was promoted to become Upper Moon Six of the Twelve Demon Moons due to his power and confronted Zenitsu as a rematch he always desired.
Shinobu Kocho is a capable Demon Slayer whose worthy of being the Insect Hashira. That being said, she's arguably the weakest Hashira when it comes to pure strength.
But the crowning moment of his achievements is when he epically slices off Daki's head and makes a run for it—after all, she won't die until her brother's head is also sliced. Unfortunately, Gyutaro spots Inosuke and stabs him right through where his heart should be with a sickle imbued with deadly poison.
Nezuko Kamado
Zenitsu also protects Nezuko multiple times when she is in danger, evident during Zenitsu's first meeting with Inosuke Hashibira and the battle against Enmu in the train. Eventually Zenitsu and Nezuko would marry and start a family as evidenced by their descendants.
Unfortunately, the answer to this question would be, no, he did not. Zenitsu, along with Tanjiro and Inosuke got way stronger than average corps members with training. In fact, he became one of the very few to even invent a new form of Thunder Breathing. However, his dream of becoming a Hashira was never realized.
The reason for this is pretty simple. Zenitsu wasn't able to master the other 5 forms. He never wanted to learn any breathing techniques. or fighting techniques, nor he wanted to join the Demon Slayer Corps. He was forced, not in a bad way, to train because his master, Jigger Okuwajima, saw potential in him.
Jigoro Kuwajima (桑島 慈悟郎, Kuwajima Jigorō) is a supporting protagonist of the popular manga and anime series, Demon Slayer: Kimetsu No Yaiba. He is a former member of the Demon Slayer Corps, the previous Thunder Hashira and the former mentor of Zenitsu Agatsuma and Kaigaku.
Zenitsu mastered the first form to its full capacity but failed to learn the rest. However, the first form itself is extremely difficult. With his master gone, Zenitsu can no longer learn the remaining five forms. Therefore, during his fight with Kaigaku, an Upper Moon Six, he created a 7th form.
As a demon, Kaigaku had eaten many people and became powerful enough to become the new Upper Rank Six of the Twelve Kizuki by the start of the Infinity Castle Arc.
Zenitsu's Flaming Thunder God became his most potent attack as he used it to decapitate an upper-rank demon in the Demon Slayer manga series. When using the Flaming Thunder God attack, the user sprints forward at incredible speeds while simultaneously unleashing a single slash and a dragon with lightning-like features.
5 Hashiras who end up dying in Demon Slayer (and how it happens) Demon Slayer has showcased many characters that vary in personality, strength, and overall combat abilities.
Tanjiro does not die in Demon Slayer though he nearly gave up the ghost in grueling battles against demons such as Rui and Daki. Even when he is severely wounded in his fight against the Demon King named Muzan and on the verge of death, he is brought back to life.
1 Mitsuri & Obanai
Unfortunately, the Serpent Hashira also succumbed to his injuries. He and Mitsuri confessed their love and died together shortly after.
But there is one who is the friendliest of them all, and that is Kiyogiro Rangoku, the Flame Hashira. Among the pillars, there is not a single negative thing revolving Rangoku. Such an honest guy, and his character influences others positively. In Demon Slayer, Liu and Rangoku are not shown to have any interactions.
The Wind Hashira has one of the saddest backstories in Demon Slayer. His mother had turned into a demon and had killed five of his siblings. He was forced to kill his own mother in an attempt to save his only remaining brother, Genya.
It's implied that the characters from the original series have all since died and have been reincarnated in modern day Tokyo in the final chapter of the series, but two key characters confirm that Nezuko Kamado and Zenitsu Agatsuma eventually did have a family together as their great grandchildren, Yoshiteru and Toko ...
The first demon that is said to have existed was Muzan Kibutsuji. The one who turned him into a demon was a generous doctor from the Heian Period, who wanted to save Muzan from death since, at the time, he was diagnosed with a disease which would kill him before he turned twenty.
The divine nature of sun breathing: Tanjiro's link to Yoriichi. The flashback also reveals that Yoriichi had a twin brother named Michikatsu Tsugikuni, who became a Demon Slayer but later turned into a demon and became Upper Moon One, Kokushibo.