In the middle of the night, in a area sorrounded by mist, two demon slayers were approaching a disrepaired castle. Alongside them, there were two Hashiras: Obanai Iguro, the Serpent Hashira, and Sanemi Shinazugawa, the Wind Hashira. "What is this place?" asked Sanemi. "It seems like this castle fell in disrepair during the revolution, forgotten and abandoned because it's in a remote location," replied Obanai. "I don't like when those demons act like lords. Let's behead all of them," said Sanemi. Then, the Wind Hashira noticed a demon, carrying a woman on his shoulders. "There he is!" he exclaimed, running after the demon. "Wait for us, Shinazugawa!" said Obanai, running behind Sanemi. As the four of them entered inside the castle, they were circled by lots of demons. "Seems like we're not alone..." muttered Sanemi. In a blink of an eye, both Sanemi and Obanai moved their swords skillfully, killing the demons with a single hit. "You two, get back. The Wind Hashira and I will take it from here," said Obanai. "You're in the way, amateurs. Leave the hardest part to the professionals," said Sanemi. The two slayers got back, leaving Sanemi and Obanai alone. "Shinazugawa, something strange's going on here..." said the Serpent Hashira. "Yeah, I don't like it," said the Wind Hashira. "I've never seen so many demons swarming in one place."
Suddenly, the two Hashiras heard a scream. "Please, help!" it was the voice of a woman. Probably, the one that demon was carrying on his shoulders. But then, a bunch of demons appeared. "Wind Breathing: Second Form -- Claws Purifying Wind!" exclaimed Sanemi, killing almost all of them. Then, behind him, with a jump, Obanai appeared. "Serpent Breathing: Fifth Form -- Slithering Serpent," he said, clearing the way and killing the last few demons. "I didn't ask for your help!" exclaimed Sanemi. "I helped you anyway," said Obanai. From nearby, the demon with the demon was still alive. (This strength... I knew it, they're not ordinary demon slayers, they're Hashiras!) realized the demon. "Hey, demon! Leave that woman and your head here!" exclaimed Sanemi, running after the demon. The demon jumped from the window, getting outside the castle. After slicing some demons, Sanemi reached the roof. Obanai reached him shortly after. "Our absolute priority is to save that woman, no matter what!" said Sanemi. "Fine. I'll cover your back..." said Obanai. Sanemi nodded, and he jumped away, searching for the demon with the woman. "Serpent Breathing: Third Form -- Coil Choke," said Obanai, slashing the demons who kept appearing.
As for Sanemi, he managed to reach the top of the roof and corner the demon. "Listen, you can't win even if you gather fries, just give up and die," said the Hashira. In response, the demon sent other demons towards Sanemi. "Wind Breathing: Fourth Form -- Rising Dust Storm," said Sanemi. In a blink of an eye, all demons disappeared, as a bloodrain created and covered Sanemi. In a desperate attempt to win then, the demon threw the woman away. Fortunately, Obanai managed to catch her on the fly. Then, the two Hashiras ran after the demon, who jumped off the roof. But as they did the same, they found themselves in the Infinity Castle. "What the..." muttered Obanai. "Come here, filthy bastard!" exclaimed Sanemi, aiming to attack the demon. But then, once again, as for magic, the two Hashiras to the place where they were earlier. How could the Infinity Castle appear and disappear in such a way? "What happened?" asked Obanai. "How the hell am I supposed to know?" replied Sanemi.
Far away, on a wagon on the way for the headquarters, Kanao Tsuyuri was sitting. The sun rised. After a while, Kanao arrived at the headquarters. The girl slowly walked towards Shinobu's room. "Sensei... I have just returned from my mission," she said. Shinobu nodded, and the two girls started walking around. "The matter of the Swordsmith Village was just like I told you the other day," said Shinobu. "Tokito, Kanroji, Goku-kun and his friends have defeated two Upper Moons, even if it costed Kamado's life..." she said. "Goku-kun is still shaken and traumatized from that day... He stopped talking, just like Tomioka-san..." she continued. "Is there anything we can do to cheer him up?" asked Kanao. "Maybe. If my calculations are correct, we'll hear him jumping and smiling in happiness in a few minutes," explained Shinobu. "Did you all prepare a surprise for him?" asked Kanao. "Yeah, we did. Everyone is sad to see Goku-kun so sad. Not even Kamado's best friends -- Agatsuma and Hashibira -- seemed to be so shaken by his death," said Shinobu. "However, after the fight, Nezuko even managed to conquer the sun... Probably, Muzan will use his demons to to take Nezuko away. Even if I don't care Goku-kun will ever allow it," said Shinobu. "Oh, yeah, he made a promise to Tanjiro..." muttered Kanao.
Meanwhile, in his room, Goku was sitting on the floor, in silnce. Both of his swords were placed next to him, his hanafuda earrings on, as always. His eyepatch on his right eye was still at its place. In his mind, Goku replayed that day. (I'll never forgive myself...) he thought. Suddenly, on his window, Rin -- his Kasugai crow -- knocked with her beak. On her left leg, there was a letter. "What's going on, Rin?" asked Goku. "Caw! A letter for you from Ubuyashiki-dono!" said Rin. "Huh? A letter from Ubuyashiki? For me?" repeated Goku. Slowly, he opened the letter, and with his only remained eye, he read the letter -- and for the first time in what seemed a lifetime, Goku smiled.
"Dear Tsugikuni, it's Ubuyashiki. I'm very sick, so I'm sorry I couldn't give this letter to you by myself. However, since the happenings at the Swordsmith Village, you became even more taciturn and nonchalant than before. So, me and the Hashira decided to surprise you to cheer you up. Think about it: You perfectly know how to use Sun Breathing. You beheaded not one, not two, but the beauty of three Upper Moons. You're strong, Tsugikuni. And so, as the householder, and after receiving the approval of every Hashira, I name you the new Sun Hashira."
"YEEEEAAAH!" beamed Goku, jumping outside the window. "I'm a Hashira! I'm a Hashira! I'm a Hashira!" he kept repeating, now believing what just happened. "Told you," said Shinobu, from afar. For the first time in what felt an eternity, Shinobu saw a smile on Goku's face. "It's been a long time since I last saw him this happy..." said Kanao. Goku, still jumping, noticed the two girls. "Hey, Shinobu-chan! Kanao-chan!" he exclaimed, waving a hand and approaching. "Why so happy, Goku-kun?" asked Shinobu. "Ubuyashiki named me the new Sun Hashira! You voted for me, right?" he said. "Of course I did. Everyone did," said Shinobu. "Yes! I'm so happy that I would kiss you!" exclaimed Goku. In that moment, Shinobu blushed a bit. (Oh, right... She doesn't know I have a crush on her...) remembered Goku. "Uh, nevermind... Forget I said that..." dismissed Goku, walking away. (Is he... Is he back normal? Is he back to smile, and to be the Goku I once knew, six moths ago?) wondered Shinobu.
In that moment, Goku forgot about evertyhing. He forgot to feel guilty, he forgot Tanjiro's death, he forgot everything. In that moment, only one thing counted:
Goku Tsugikuni just became a Hashira.
Chapter 41 - End.