Zenitsu's descendants live in their own large mansion while descendants of his best friend Tanjiro Kamado live in an apartment in the present era. This indicates that somewhere along the line, Agatsuma family became rich.
When he saw how Nezuko wasn't two-faced and was truly kind, he became so happy that he saw paradise for a moment and almost ascended to heaven. Zenitsu's debt is estimated to be around 600,000 yen in modern currency.
Zenitsu was not raised by his parents so he did not have any proper guidance. When he was young, Zenitsu fell in love with a girl and decided to give her money to appeal to her, however the girl ended up running away with another guy leaving Zenitsu drowning in debt.
While unconscious, Zenitsu is a force to be reckoned with, but his actual power is discovered when he is awake. While awake, Zenitsu was able to match the upper rank six, Kaigaku. He was also able to keep up with the Demon King, though he was in a weakened state during this battle.
Zenitsu, an orphan, was always grateful to the old man who never abandoned or gave up on him, unlike the rest of the people in his life. Zenitsu's hair starts falling out, as the spider demon warned him it would, and he faints in fear.
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.
Most Demon Slayers get crows, but the symbology of the sparrow makes Chuntarothe the perfect fit for Zenitsu. While all other Demon Slayers are gifted a crow after final selection, Zenitsu is assigned a sparrow instead.
Why Zenitsu could not become a Hashira in Demon Slayer. Fans have wondered whether Zenitsu ever got to realize his dream of becoming a Hashira at all. 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.
Given how talented Tanjiro is, it's likely he'd defeat Zenitsu, even if the latter could fall asleep and call on his powers. Tanjiro's demonstrated his ability to take down more powerful demons and adapt to training on more than one occasion, so it just makes sense.
Exploring Zenitsu's fighting abilities in Demon Slayer
Zenitsu has perfected the first form only and is seen performing it only when he's unconscious. But the manga shows that he can fight without fainting or going unconscious.
When facing Kaigaku during the Infinity Castle arc, Zenitsu debuts his brand new exclusive Seventh Form to Thunder Breathing. With this, Zenitsu finally has more than one tool in his arsenal and has overcome his own personal doubts and fears.
Zenitsu is then taken in by Jigoro Kuwajima (who also takes care of his debt). Jigoro is a former Thunder Hashira and takes Zenitsu in to train him in the ways of Thunder Breathing. The two develop a fantastic bond, similar to a grandfather and grandson, hence why Zenitsu calls Jigoro Gramps.
Zenitsu has such a wide range of emotions, all of which have their extremes. It's part of what helps make Zenitsu such a likable and memorable character, as well as making him really funny in the process.
So in a nutshell, Zenitsu wasn't able to master the other five forms, but later in the Infinity Castle Arc, during the battle with Kaigaku, Upper-Rank Six Demon, he created a Seventh Form: Flaming Thunder God.
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.
1) Inosuke Hashibira
Although Inosuke possesses immense strength and endurance, he's no match for Zenitsu's insane speed and his Thunder Breathing.
Overall, Zenitsu is an extraordinary powerful Demon Slayer capable of singlehandedly bringing down an Upper Rank, which said to be able to overpower 5 Hashira, in 10 minutes, albeit he would have beheaded Kaigaku in a heartbeat if it wasn't for his feelings of melancholy and pity.
Fortunately, Zenitsu was able to single handedly beat the Upper Moon 6. Not only did he defeat the demon, he also created a seventh form called the Flaming Thunder God. These are the demons who have been given the title of Upper Moon 6 in Demon Slayer.
Despite her petite appearance, Mitsuri Kanroji has a special muscular composition that makes her muscles eight times denser than an ordinary human's. She is also more flexible than the other Hashira. These two strengths balance out her being the slowest runner out of all the Hashira.
13/15 Zenitsu Agatsuma Defeated An Upper Moon On His Own
He falls asleep when he crumbles under the weight of his own fear, and his body fights on instinct alone, utilizing his Thunder Breathing Style. He proved that he can be a capable fighter even while awake, defeating Upper Moon 6 on his own.
Tanjiro, Zenitsu, and Inosuke didn't become Hashira since they aren't ranked Kinoe, one of the requirements to become a Hashira.
Zenitsu always performs a single form because that is the only form he knows. His attack always start with this positioning, and end result is this way.
Kaigaku overpowering Zenitsu with his Blood Demon Art-enhanced techniques. Overall Abilities: As a member of the Upper Ranks, Kaigaku is immensely powerful. Combined with his swordsmanship skills as a proficient Demon Slayer, Kaigaku is an extremely deadly demon.
Zenitsu Agatsuma only uses one move (in anime up till now) , I.E. Thunderclap and Flash, because he hasn't learned the other Thunder Breathing Forms. He never wanted to learn any breathing techniques or fighting techniques nor he wanted to join the Demon Slayer Corps.