During the mission with Uzui in the Entertainment District, Tanjiro and his comrades come out victorious in the fierce battle to the death against Upper Six Demons, Daki and Gyutaro. The death of the Upper Rank Demons that Tanjiro and his comrades succeeded in results in a shift in a situation that has remained unchanged for a hundred years, and brings about a disturbance between Muzan Kibutsuji and the demons...

After learning that he made Haganezuka angry for chipping his sword, Tanjiro and Nezuko head to the village where the swordsmiths live. At the Swordsmith Village, one of the securely hidden and most important bases for the members of the Demon Slayer Corps, he reunites with Genya Shinazugawa, who joined the Demon Slayer Corps the same time as Tanjiro, and the Love Hashira, Mitsuri Kanroji. After hearing about a secret weapon from Mitsuri ...

Tanjiro begins his training with Yoriichi Type Zero and is pushed to the limits by Kotetsu's relentless coaching and extreme training. Through this experience, Tanjiro masters a new skill of predicting where the opponent's next move will hit by using his sense of smell. During his training, Tanjiro lands a blow on Yoriichi Type Zero and ends up destroying it, but a sword from over 300 years ago appears from inside...

"An Upper Rank demon appears out of nowhere in front of Tanjiro and Muichiro. Muichiro cuts off the demon's head, but its body separates into two and sends Muichiro flying. Tanjiro, Nezuko, and Genya enter the fight against the two demons, however, the demons split again to further multiply and their attack separates Tanjiro from the rest of the group. Meanwhile, Muichiro rescues Kotetsu, who is being attacked by a goldfish demon...

Thanks to Touka's quick thinking and Marguerite's "Princess's Etiquette ", the party was able to corner Leland. However, the situation was reversed when a high-ranked demon intervened. Touka is seriously wounded and in a great crisis. At that moment, Marguerite's unintentional action produced a miracle. Receiving her feelings, the revived Touka transforms his holy sword huge and swings it down at the demon...

Tanjiro and his comrades struggle to fight against Hantengu's four split bodies; however, he successfully severs three of their necks while wielding the bright red sword burned by the power of Nezuko's blood. He realizes that Genya had cut off the last remaining demon's neck and sees Genya holding the demon's head, but notices that he appears to look different...

Genya aims for the neck of the fifth demon that split off from Hantengu, but the demon's neck is shockingly hard, and his sword snaps in half in his attempt to strike it. His gun is also ineffective and Genya is driven into a corner. Realizing that he is unable to sever the neck by himself, he entrusts defeating the fifth demon, which is believed to be the main body, to Tanjiro...

Despite being wounded himself, Kotetsu tries to rescue Muichiro who is trapped inside of the water that Gyokko created. Seeing Kotetsu sacrificing himself to save him, Muichiro is reminded of Tanjiro's words, which triggers a memory of his father. Receiving the air that Kotetsu blew into the water, Muichiro unleashes a strike with his Mist Breathing at full strength and gets himself out of the water, however...

After defeating the goldfish demons, Muichiro heads to the studio where Haganezuka and Kanamori are. There, in order to disrupt Haganezuka's focus on whetting the sword, Gyokko was attempting to take Kanamori for hostage. Muichiro arrives in the nick of time, receives the Nichirin Sword from Kanamori, and challenges Gyokko once again...! 无一郎将金鱼鬼群打倒后，前往钢铁冢跟铁穴森所在的工作小屋。在那里，为了让持续磨刀的钢铁冢无法继续专心下去，玉壶正打算将铁穴森作为人质。在千钧一发之际赶到的无一郎，从铁穴森手中获得新的日轮刀，再次向玉壶发起挑战――！

Tanjiro, Nezuko, and Genya are struggling through an arduous battle against Zohakuten and his five tree dragons. They are forced to fight defensively against the tree dragons using the four emotion demon's powers, and Tanjiro is swallowed by one of them amidst the fight. Just as Tanjiro is close to meeting his demise, Mitsuri arrives in the nick of time and rescues him...

As Mitsuri holds off Zohakuten, Tanjiro, Nezuko, and Genya use this time to chase after Hantengu's main body. The three manage to find the tree ball that Hantengu is hiding in, but, when they slice it open, they find that it is completely empty. Hantengu makes a run for it again, and Tanjiro and the others continue chasing him. Seeing Hantengu running about, Genya snaps and hurls a tree at him, and Nezuko jumps at him...!