Demon Slayer Season 4 is under production and Ufotable recently announced its teaser visual. This has kept fans at bay, with many anime fans wondering whether Inosuke and Zenitsu would return to the Hashira Training Arc or not and if they would make their way to the Final Battle Arc. The Swordsmith Village Arc did not have Zenitsu and Inosuke but will we get to see them on center stage in the upcoming Infinity Castle Arc?
Demon Slayer Season 4: Zenitsu vs Kaigaku in the battle at the Infinity Castle
Demon Slayer Season 4 leads Zenitsu as a prepared swordsman into the Infinity Castle Arc. Zenitsu encounters Kaigaku, a senior of Zenitsu, at the Infinity Castle. They engage in a furious conversation and Kaigaku insults Jigoro, Zenitsu’s teacher. Their battle begins with Kaigaku using Thunder Breathing Fourth Form: Distant Thunder and attempts to kill Zenitsu, however, the latter easily slashes through this.
This zenitsu>>>>>>> https://t.co/VHZbBvx4dp pic.twitter.com/hmpA2FxU9r
— Tan (@Onlyfact_s) June 21, 2023
Kaigaku employs several breathing forms to attack Zenitsu, including the Thunder Breathing Third Form and Thunder Breathing Sixth Form.
Zenitsu starts falling, but at this moment he realizes and looks back at his relationship with Kaigaku. He jumps onto a wall and reflects at Kaigaku with his own breathing form- Thunder Breathing Seventh Form: Honoikazuchi no Kami and beheads Kaigaku.

The battle ends with Kaigaku cursing Zenitsu and Zenitsu being rescued by Yushiro. He gets into a dream where his master, Jigoro, tells him, “Zenitsu, you are my pride and joy.”
Inosuke fights alongside Kanao against Upper Rank Two Doma
Doma defeats and consumes Shinobu, the Insect Hashira. In a fit of rage, Kanao attacks Doma and they engage in a gruesome battle.
But, while Doma snatches Kanao’s blade and was about to kill her, Inosuke enters from the ceiling and defends Kanao. Doma and Inosuke start exchanging attacks at each other at alarming rates and soon he is able to slash Doma through his eyes.

Doma reveals that he indeed killed Inosuke’s mother as he gets a look at Inosuke’s familiar facial features. Inosuke vows to put Doma through hell and thanks him instead.
The battle ensues but Doma soon tries to retreat and kill the rest of the Demon Slayers. But as he was about to leave the room, his hands are sliced off and he realized that he instead consumed a self-poisoned Shinobu. During the final strikes, Inosuke and Kanao together behead Doma as he is weakened by Shinobu’s poison.
Inosuke and Zenitsu in Demon Slayer Season 4

Inosuke and Zenitsu will prepare for the final battle against Muzan in the Hashira Training Arc. Demon Slayer Season 4 will strongly focus on the duo and they will develop greatly in terms of ability and spirit.
Moreover, Inosuke, and Zenitsu will also get a central stage in the final battle against Muzan Kibutsuji in the Infinity Castle Arc. They will fight alongside other demon slayers to keep Muzan at bay until dawn. They will assist Tanjiro and the other Hashiras in fending off Muzan’s attacks and their contribution will be greatly valued during the final battle.
Conclusion
Inosuke and Zenitsu in Demon Slayer Season 4 will become important side characters and they will play major roles in the entire story’s motivations during the Infinity Castle Arc. Moreover, they will be highly accredited with bringing about crucial moments into the narrative and will take a central stage in defining the essence of the story.