Goku, Tanjiro, and Nezuko were chasing Hantengu's main body. Genya threw a tree at the demon, but without success.
(I'm going to slice your fucking head, you unworthy-to-be-living demon!) thought Tanjiro, who was ahead of Goku and Nezuko.
(Two months ago, I was the one to behead the demon... This time, I'll leave the kill to Tanjiro-kun...) thought Goku. Suddenly, Nezuko jumped and reached Hantengu, attacking him with her claws. Unfortunately, Hantengu jumped and dodged.
"Dammit! He runs so fast!" exclaimed Genya, who reached Nezuko and the others.
(We'll soon reach our limit... And it's almost daybreak!) thought Tanjiro, who was behind everyone. (We're not gonna let him win...)
Tanjiro fell on his knees. (I can't even run anymore...)
But then, Tanjiro remembered something Zenitsu told him one day.
"Thunder Breathing's all about focusing on your legs the most."
In that moment, Tanjiro understood what to do. The boy concentrated all his strength in his legs. Then, he rushed forward, surpassing everyone and reaching Hantengu.
"It's over for you, demon!" exclaimed Tanjiro, smashing his katana against Hantengu's neck.
(Yes! Tanjiro-kun's gonna do it...) thought Goku.
But then, Hantengu turned his head. "Don't you feel the least bit sorry for me?"
Suddenly, Hantengu's body grew bigger, and he put his hand on Tanjiro's mouth, suffocating him. "Don't you dare bully the weak!"
"Let Tanjiro-kun go!" exclaimed Goku, slashing Hantengu's arm. But then, with the other arm, Hantengu delivered a fatal blow to Tanjiro's chest just before Goku's eye.
In that moment, Goku froze, and Hantengu had the time to escape.
"Ta... Tanjiro-kun..." muttered Goku, his voice barely audible.
"Go... Goku..." muttered Tanjiro, lying on the floor, losing an insane amount of blood.
"Hold on, Tanjiro-kun! Don't die!" exclaimed Goku, kneeling and panicking, searching for something to heal Tanjiro.
"Goku, please... Take my earrings with you..." muttered Tanjiro.
"No! You won't die! I order you not to die!" exclaimed Goku.
"Goku, we gotta go! The demon's running away!" said Genya.
"SHUT UP!" yelled Goku.
"Goku, please... Protect... Nezuko for me..." said Tanjiro, slowly closing his eyes.
"Tanjiro-kun!" shouted Goku. But then, Goku felt it: In that moment, Tanjiro's heartbeat stopped.
(His heart stopped...) realized the boy.
Genya, from behind, realized the situation too. (Did... Did Tanjiro die...?)
"Hantengu..." muttered Goku. "He's... He's going to pay..."
Goku took Tanjiro's earrings. "I take these with me. In memory of you... I'm gonna avenge you, Tanjiro-kun..."
Goku's body heat grew hotter. "I'M GONNA AVENGE YOU!"
Without reasoning, Goku dashed forward at tremendous speed, not waiting for Nezuko or Genya.
"COME HERE, YOU PIECE OF SHIT!" he yelled, reaching Hantengu in a fraction of a second and slamming his blade against the demon's head. However, the forest ended, and both of them fell.
Nezuko arrived just in time to try to help Goku not to fall, but she fell too.
"Goku! Nezuko!" exclaimed Genya from up there. Hantengu landed on the floor with a thud, without the arms, that Goku severed earlier.
(I can't regenerate properly... I need human flesh...) He thought, slowly walking to search for something to eat, with Goku's sword stuck to his neck. But then, Hantengu heard a voice.
"I'm not gonna let you escape!"
It was Goku, blocked on a trunk in mid-air, with his forehead and right side of the face covered in blood.
"You will pay for what you did to my best friend!" he exclaimed, jumping off the trunk and landing on the floor.
When Goku landed, he saw that Nezuko fainted on the floor.
"Nezuko-chan, are you okay?" he asked. Hantengu continued to run, and finally, he smelled something: three villagers with pink masks.
"There! Human flesh!"
Goku turned and saw Hantengu chasing the three villagers. (My sword is stuck in his neck... How am I supposed to finish him off...?)
Then, he heard a voice. "Goku-kun..."
(Whose voice is this...?) wondered Goku. Then, he noticed: From up there, there were Muichiro, Haganezuka, and Kotetsu. The Mist Hashira took a sword and threw it at Goku.
"Use that! That's your father's sword!" exclaimed Muichiro, panting. Goku took a look at the sword, its red blade reflecting his face. In that moment, Goku grabbed the katana. When the boy held the sword in his hand, memories of his father rushed through his mind.
(I'm ready... I'm coming for you, Tanjiro-kun's murdered!) thought Goku. Then, using Total Concentration, Goku dashed forward. "IT'S OVER FOR YOU, DEMON!"
He slammed the katana on the demon's neck. "Sun Breathing: Second Form -- Clear Blue Sky!"
With an insane struggle, the boy beheaded the Upper Rank Demon.
(I did it... I finally behead it...) thought Goku, panting.
Then, he noticed something: the sun was rising.
(Shit... I have to protect Nezuko-chan...!) realized Goku, running back to the girl. But for some reason, Nezuko started to run towards Goku.
"No! You don't have to come this way, Nezuko-chan!" said Goku. But Nezuko didn't listen. Then, Goku noticed something: Nezuko was pointing at something. As he turned, Goku saw that Hantengu was still alive, and he was running after the three villagers.
(He's still alive? How? I beheaded him!) wondered Goku. Then, he realized: The kanji on Hantengu's beheaded head's tongue was "resentment", not "fear".
(That wasn't the main body...) realized the boy. (I have to finish him off, but I can't leave Nezuko-chan alone!)
Once again, Goku was panicking. Suddenly, he held Nezuko in his arms, protecting her from sunlight. "I'm not letting you die, Nezuko-chan!"
(His last wish... was for me to protect her. I will respect his last wish.)
"Nezuko-chan! Shrink your body like you always do!" he exclaimed. Nezuko, who started to burn up, shrank her body.
(What should I do? I'm panicking...) thought Goku. (Tanjiro-kun... Why did you die now? What would you have done? If I let Nezuko-chan die too... Not only will I remain alone, but I'll also not respect Tanjiro's wish... I promised him...)
But then, just when Goku was panicking, Nezuko kicked him away, directing him towards the demon. Goku, in mid-air, saw Nezuko's burnt body.
And in that moment, without even knowing why, all the memories with the Kamado brothers rushed through Goku's mind.
Their first encounter at the Drum Mansion, their regroupment on Mount Natagumo, their mission on the Mugen Train, the fight against Daki and Gyutaro... And now this.
(Nezuko-chan... You kicked me towards the demon... I will not disappoint you!)
The boy landed on the floor, struggling to hold back tears. "Let's end this."
Then, he jumped towards Hantengu.
(The real body is inside the heart... I have to slice all of him!) thought Goku in mid-air. "Sun Breathing: Thirteenth Form -- Perpetual Light!"
All the twelve forms of the Sun Breathing were performed, and Hantengu's body was sliced into several tiny pieces. Finally, the real Hantengu appeared.
"This... THIS IS FOR TANJIRO-KUN!" Goku roared. And finally, Goku beheaded the Upper Rank Demon. Also, thanks to the sunlight, Hantengu disappeared.
Finally, the fight was over.
Chapter 39 - End