Season 4 Episode 7 of Demon Slayer marked the coming of the next arc within the series with the arrival of a forboding letter given to Zenitsu. Zenitsu becomes quiet, his friends and fans alike leaving them wondering just what exactly was in that letter.
There will be spoilers ahead for anyone who has not read the Demon Slayer manga.
What Was In Zenitsu’s Letter In Demon Slayer?
Zenistu receives a letter from Chuntaro, his sparrow assigned to him for assignments and correspondences within the Demon Slayer organization. In this letter is a notice that Zenitsu’s instructor, Jigoro Kuwajima, has killed himself through Seppuku to atone for the acts of one of his students.
Seppuku is a Japanese ritualistic suicide where the person will disembowel themselves. It was often seen as a way to restore honor for themselves and their family and was usually reserved for samurai as a part of their warrior code. It was a very slow and painful death if there was no person standing behind them to quickly put them out of their misery. In Jigoro’s case, he committed the act alone, making his death long and agonizing.
When Are The Contents of Zenitsu’s Letter Revealed?
The contents of the letter and the story behind it are not revealed until the Infinity Castle arc when Zentisu confronts Kaigaku. Zenitsu comes face to face with Kaigaku, his once-fellow disciple under Jigoro. It is revealed that Jigoro killed himself when he learned that Kaigaku had become one of the Twelve Kizuki, taking the place of Daki and Gyutaro as the Upper Rank Six demon. Jigoro’s Thunder Breathing technique had gotten into the hands of demons, aiding in innocent deaths, and he could not find a way to atone except through death.
While still a demon slayer, Kaigaku fought with Kokushibo, Upper Rank One of the Twelve Kizuki, and quickly lost. Kokushibo gives him the choice to either die or join the demons. Thanks to Kaigaku’s warped sense of priorities, he chooses to join the demons and quickly ascends the ranks to join the Upper Rank demons.
Zenitsu gets his chance to fight Kaigaku one-on-one in the Infinity arc, showing his growth as a character when he coldly deals with the Upper Rank demon while still awake, unlike his previous fights.
Get the recap for Demon Slayer season 4 episode 7 to get a refresher on what else happens alongside the appearance of the ominous letter.