During Hashira Training, Zenitsu receives word that Kaigaku had become a demon, and that Jigoro committed seppuku as atonement.
Zenitsu is a powerful Demon Slayer and a member of the Demon Slayer Corps. Although he was originally roped into joining the Corps by his mentor Jigoro Kuwajima, Zenitsu later realizes the importance of the Demon Slayer Corps.
One of the characters that people mistake for Zenitsu's brother in the series is Kaigaku. However, this is not true, and Kaigaku is just his senior in the dojo where the two trained under the guidance of Jigoro, and was also adopted by the former Thunder Hashira.
He had a younger brother (Zenitsu) and two younger sisters (Ayeka and Kina)—all of them succumbed to despair once they learned of his death. After he learned the news of his younger sister`s death, Kaigaku was devastated and sent a gift back home for his younger sister - a pressed flower crown - that went on her grave.
Kokushibo offered Muzan's blood to turn Kaigaku into a demon, which Kaikagu accepted, causing his transformation into a man-eating savage.
He abused Zenitsu Agatsuma. He betrayed the Demon Slayer Corps, driving his master to suicide.
Zenitsu is one of the main protagonists in Demon Slayer. After properly meeting him, Tanjiro will become his friend and comrade.
He is a demon affiliated with the Twelve Kizuki, holding the position of Upper Rank Six ( 上 じょう 弦 げん の 陸 ろく , Jōgen no Roku?), replacing Daki and Gyutaro after their deaths.
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.
A spider demon drops from the sky and tells Zenitsu that there is no point in running away. The spider demon explains that the spider that bit Zenitsu earlier was one of his, and Zenitsu has been poisoned and will slowly start turning into a spider.
Zenitsu Agatsuma
Zenitsu trained in the "Thunder Breathing" (雷の呼吸, Kaminari no kokyū) style by the former Thunder Hashira but was only able to learn the first form, and because of this he often belittles himself, despite the fact that he is talented.
Yoshiteru Agatsuma ( 我 あが 妻 つま 善 よし 照 てる , Agatsuma Yoshiteru?) is the great-grandson of Zenitsu Agatsuma and Nezuko Kamado and the younger brother of Toko Agatsuma, who is a teenage student.
Demon Slayers are known for their strength and bravery in battle, but not Zenitsu. Despite his cowardice, he's one of the strongest in the series. The life of a demon slayer is one of hardship.
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.
Unfortunately, Gyutaro spots Inosuke and stabs him right through where his heart should be with a sickle imbued with deadly poison.
Nezuko marries Zenitsu Agatsuma in the Demon Slayer series.
However, in the Demon Slayer manga Muzan reveals his motivation for attacking the Kamado family. It turns out that Muzan attacked the Kamado family and specifically turned Nezuko into a demon in an attempt to create a demon that would be able to withstand being in the sunlight.
Zenitsu is clearly on the same level as Hashira. If we compare him to Shinobu, his speed is far better, while she lacks quite a lot in raw power. There is a good chance that he could beat Shinobu if the two decide to fight.
But, comparing the two characters in their best forms, Zenitsu might be just a tad bit faster owing to his Godspeed move.
Tanjiro Is Strong, and Stronger than Zenitsu as he uses Sun Breathing.
Upon seeing her for the first time, Zenitsu falls in love with Nezuko at first sight. She apparently views Zenitsu as a "weird dandelion" and did not initially seem to reciprocate his feelings. Although the two are rarely seen interacting together, Zenitsu treats her with affection and care.
1 Gyomei Himejima - The Stone Hashira
The oldest of the bunch, the Stone Hashira, Gyomei Himejima is 27 years old. He is a giant with a soft heart who cries over insignificant things, but despite all that, he is easily one of the most powerful Hashiras.
Some of the characters who have faced Yoriichi and survived
This happened due to a treatment that had gone wrong. While he was being treated, Muzan killed the doctor because he was not able to observe any results.