Zenitsu Agatsuma vs Tongue Demon is a fight that took place in the House of Drums. It focuses on the battle between the demon slayer Zenitsu Agatsuma, against the tongue demon.
As they walk around the Tsuzumi Mansion, a clearly terrified Zenitsu can be seen clinging to Shoichi’s hand as the pair try to find an exit. After calling Zenitsu and being scolded by the latter for making noise, Shoichi tells Zenitsu that he doesn’t feel safe around him, especially considering that Zenitsu was scared. Zenitsu begins to apologize profusely and tells him that they should keep quiet to avoid being attacked by demons, just as the Tongue Demon appears in front of them.
Zenitsu, even more terrified than before, desperately asks the demon to stay back, adding that saying neither him nor Shoichi wouldn’t taste good as they begin to run away. The demon simply responds by saying that he wouldn’t know how they would taste if he didn’t try, and proceeds to chase and attack them.
After running into a room, Zenitsu collapses on the ground from the extreme fear he is facing, telling Shoichi to escape and leave him. The young boy immediately refuses and Zenitsu feels compelled to save Shoichi. As the Tongue Demon approaches them, Zenitsu falls asleep due to his fear and the stress of the current situation catching up with him. Shoichi begs him to wake up just as the Tongue Demon sticks out his tongue.
An unexpected move occurs when the Demon’s tongue is cut out by Zenitsu as the latter stands with his head down, his subconscious supporting him. He gets into position to use Thunder Breath, First Form: Thunder Clap and Flash, Zenitsu prepares to decapitate the Tongue Demon without hesitation. With a swift flick and direct hit from Zenitsu’s Nichirin Blade, the demon’s head now lies on the ground, while Zenitsu easily carries out his plans; he is now victorious over the demon in battle.
Shoichi gapes as he watches Zenitsu wake up and scream at the sight of the deceased Demon’s head, now decapitated from his body. The confused Demon Slayer misunderstands the situation and begins to express extreme gratitude to Shoichi for “saving” the pair, also telling him that he should have left his extreme strength much sooner. Shoichi, who no longer knows what to say, decides not to say anything and tells Zenitsu that they have to leave.