Episode 6 of *Demon Slayer: Kimetsu no Yaiba* Season 3, titled "Aren’t You Going to Be a Hashira?", opens with Tanjiro's shock at Genya’s unnatural transformation. Suddenly, he notices that despite being decapitated, the four clones are regenerating rapidly. As he rescues Nezuko from the debris, he realizes with a jolt that there is a fifth clone lurking.
At that moment, Genya abruptly grabs Tanjiro by the throat, declaring with fierce determination that he will be the one to defeat the Upper Rank Demon and claim the title of Hashira. Tanjiro, genuinely moved, voices his full support—leaving Genya momentarily stunned and confused. Amidst their tense exchange, all the clones suddenly heal and launch a ferocious assault. Tanjiro urges Genya to hold them off with Nezuko’s help while he searches for the fifth demon.
Karaku, in his carelessness, disperses the sulfuric stench clouding the area, allowing Tanjiro to use his acute sense of smell to track down the true source—the original Hantengu, hiding underground. He directs Genya to pursue the demon while he covers for him. However, Tanjiro and Nezuko struggle to keep the relentless clones at bay.
Meanwhile, Tokito remains trapped in Gyokko’s watery prison, his breath running dangerously low as the demon lord gloats triumphantly.
Back with the clones, Aizetsu plunges his blade into Nezuko, but Tanjiro reacts with lightning speed. Sekido, observing Tanjiro’s uncanny ability to adapt, grows wary. Nezuko, too, unleashes her Blood Demon Art, intensifying Sekido’s concern. Genya, however, fails to locate Hantengu. Tanjiro tries to guide him, and Genya finally realizes the demon has shrunk to the size of a mouse. Furious at the absurdity of such a tiny foe being so formidable, Genya gives chase.
He lunges at Hantengu, slicing and shooting, but the demon proves too powerful, and Genya’s sword shatters upon impact. Just then, Sekido aims a lethal strike at Genya’s neck from behind. Resigned to his fate, knowing he cannot regenerate from a neck wound, Genya’s mind flashes back to his regrets—his longing to be recognized by his brother, Sanemi Shinazugawa, as a worthy Hashira, and his apologies for past failures.
In a poignant flashback, we see Genya’s sorrow for his mother—a small, worn figure who toiled endlessly, never sleeping, yet always shielding him from their abusive father’s wrath. One fateful night, when she fails to return home, Sanemi and Genya grow anxious. Genya insists on searching for her alongside his brother, but Sanemi, stern and protective, makes him promise to stay behind.
All of their other siblings awaken, and they spend the entire night in anxious anticipation. Genya steps up, assuming the mantle of the eldest brother, as he reassures them that Sanemi will bring their sister home safely. Just as the first light of dawn begins to paint the sky, a noise echoes through the stillness. As they rush to open the door, a figure barges in and unleashes a fatal blow upon them all. As this sinister presence lunges toward Genya, Sanemi bursts in and drags the demon away from his brother. Genya scrambles to find a doctor for his siblings, only to discover that they have all perished. In a desperate bid for help, he suddenly comes across a dazed Sanemi standing over their mother's lifeless body, having just slain her. Genya is overcome with horror and runs to her side, hurling accusations at Sanemi.
On the verge of death, Genya murmurs that he never had the chance to apologize, realizing in that moment that their mother had been transformed into a demon and that Sanemi had killed her, mistaking her for a stranger. He is consumed with guilt for not attempting to comprehend the agony his brother must have endured upon realizing he had taken their mother's life. He recalls Sanemi's words, urging them to protect their family after their father's demise. Yet, he is filled with sorrow that they have failed in this sacred duty.
Suddenly, he hears Sanemi's voice, cold and biting, declaring that someone as worthless as him could never be his brother. It is then revealed that Genya lacks the ability to wield any breathing technique, rendering him incapable of ever becoming a Hashira. At that critical juncture, Tanjiro arrives to his rescue, urging him not to surrender. As he launches an assault on Sekido, he instructs Genya to concentrate solely on slaying Hantengu.
Aizetsu charges headlong at Tanjiro, who is unable to evade the onslaught. But he soon realizes he is unharmed, for Genya has interposed himself, taking the brunt of the attack. Holes are blown through Genya's body, yet he persists. Genya admits that he is unable to kill Hantengu and entrusts the task to Tanjiro as he turns his attention to Aizetsu. Tanjiro finally locates Hantengu and draws his sword, ready for the final confrontation.
In the epilogue, Tanjiro inquires about Genya's well-being, noting that he hasn't eaten since they met at the Butterfly Mansion. Genya bristles at Tanjiro's intrusion into his affairs. Tanjiro explains that they are friends, having spent time together in the hot spring and having entered the final selection in the same year. Genya retorts that he despises Tanjiro's overly friendly demeanor, but Tanjiro simply smiles, looking forward to future collaborations with his comrade.
