During a dark and cloudy night, Tanjiro Kamado-who carried his sister Nezuko in the box on his back. And Zenitsu Agatsuma-who had his face wrapped in white bandages, excluding his orangish-yellow hair. They boarded the Mugen Train in order to rendezvous with their friends and the Flame Hashira, Kyojuro Rengoku. There were big number of civilians who also boarded the Mugen Train.
"I recognize this scent. Come on, Zenitsu." Tanjiro said after catching the scent of his friends, then grabbed Zenitsu's hand and lead him toward Inosuke, Kyojuro and Natsu. As soon as Tanjiro opened a door, he was met with a burst of wind and heard the word, "Delicious!" and it caused Tanjiro to flinch.
'Those voices. could that really be-' Tanjiro gasped when he easily recognized three Demon Slayers such as Inosuke Hashibira, Natsu Rengoku and Kyojuro Rengoku. Who were all eating a number of bento boxes that they had previously received from Tomi and Fuku, who worked in the Railway Bureau. Natsu and Kyojuro sat next to each other and Inosuke sat on the opposite side of the train eating bento boxes with his boarhide off his head.
A number of people who had boarded the Mugen Train saw them and heard them chant the word, "Delicious!" over and over again. A few people were embarrassed. Others were annoyed and started murmuring to each other in secret.
"Delicious!" Natsu chanted.
"Delicious!" Inosuke chanted.
"Delicious!" Kyojuro chanted.
"Uh..." Tanjiro paused and felt gave an embarrassing smile to them.
"Eh?" Natsu looked up and saw Tanjiro and Zenitsu present on the Mugen Traina and walked up to them. "You guys made it!"
"Yeah, we did. It took us a little while to get here, though..." Tanjiro smiled.
"It's alright. You made it and that's all that counts." Natsu smiled.
"Yeah." Tanjiro nodded, then the two of them high fived each other. As they were high fiving, Tanjiro spotted a read thread tied around Natsu's right wrist. "Hm? Hey, Natsu."
"Yeah?"
"I couldn't help but notice that thread around your wrist..." Tanjiro said.
"You mean, this?" Natsu pulled out his right arm, showing Natsu the read knot. "Yeah! Ozaki gave this to me, earlier, today."
Flashback
Earlier that morning, shortly after Hayai, the Slasher was slain by the Rengoku Brothers. Reinforcements had arrived at the train warehouse. There were a total of nine Demon Slayers who arrived at the scene as reinforcements. Two of the nine Demon Slayers who arrived were Ao, the Demon Slayer in the blue haori and Ozaki. As they waited for the medical unit to arrive, Ozaki had recognized Natsu and decided to speak to him in private.
"I'm happy you're okay." Ozaki smiled.
"I'm happy that you're okay, too, Ozaki." Natsu smiled, back.
"So, that Hashira inside is really your brother?" Ozaki asked about Kyojuro Rengoku.
"Uh-huh!" Natsu nodded. "He's the reason why I want to become a Hashira. I want to be just like him."
Ozaki chuckled. "I'm sure you do."
"Tonight, we're going on the Mugen train to protect more people. You want to come with us?"
"Mm-mmm." Ozaki kindly shook her head no. "I wish I could go with you, Natsu. But I'm afraid that I have things to do, as well."
"Oh. Well, it really nice talking to you." Natsu smiled and begun to turn away.
Ozaki gasped. "Wait!"
Natsu stopped.
"There's something that I want to give you, before you go." Ozaki said, then walked toward Natsu and pulled out a red string out of her pocket. Ozaki then took Natsu's right wrist and tied the string around it.
Natsu looked at his right wrist and noted the red string on it. "What's this?"
"It's a special string that binds two people together. It's called the Red Thread of Fate."
"The... Red Thread of Fate?" Natsu asked.
"Mm-hmm." Ozaki lightly blushed and smiled in front of Natsu.
End Flashback
"I see now." Tanjiro then pointed at Natsu's thread. "She must've given it to you as a gift."
Zenitsu then walked to them and began muffling.
"What is it, Zenitsu?" Tanjiro asked as he turned to Zenitsu.
Zenitsu continued to muffle in front of them, but his words couldn't reach their ears. Natsu and Inosuke's eyes shrunk like black dots as they were confused of what he was saying.
"I'm sorry, Zenitsu. I can't catch that." Tanjiro apologized.
"Wait, Zenitsu was allowed to leave the Butterfly Mansion?" Natsu asked.
Tanjiro embarrassingly sighed. "Well, no, to be honest. We were heading here toward the Mugen Train and Zenitsu decided to follow us all the way here, like a lost puppy." Tanjiro told Natsu, then thought of Zenitsu's condition. 'I'm worried about Zenitsu. If he takes another blow like he did back in Mount Natagumo... he might die.' Tanjiro temporarily frowned as he thought back when Rui punched Zenitsu in the face.
"Oh..." Natsu then looked at Tanjiro's box. "How's Nezuko doing in there?"
"She's doing fine." Tanjiro said.
Natsu frowned a bit. "I heard about what happened at the mansion. I'm sorry that you and Nezuko went through all of it."
"It's okay. They trust Nezuko, now. Well-most of them." Tanjiro said as he thought of two different Hashira named Sanemi Shinazugawa, who stabbed Nezuko multiple times. And he thought of another Hashira name Obanai Iguro.
"I recognize you." Kyojuro said.
"Eh?" Tanjiro suddenly looked around, until he saw Kyojuro staring at him.
"You were at the mansion." Kyojuro said.
"Yes. I am Tanjiro Kamado." Tanjiro then looked to Zenitsu. "And this is Zenitsu Agatsuma."
"Mmph!" Zenitsu muffled.
Kyojuro looked the rectangular brown box on Tanjiro's back and remembered seeing Nezuko come out of it. "Isn't there another person in there?"
"Yes. This is my sister, Nezuko." Tanjiro said, while Nezuko remain in the box.
"I remember her. Since the master had accepted her, I will keep my peace." Kyojuro easily crossed his arms.
"Hey, Tanjiro. Sit in front of us." Natsu pointed at a seat.
"Um, okay." Tanjiro said, then had taken a seat and placed Nezuko's box next to him. Zenitsu who's face was covered in bandages had sat next to Inosuke, who tried to break the glass window. Despite not seeing well, he tried to stop Inosuke from causing a ruckus by pulling on his boarhide.
"So, were you and your blonde friend ordered on a mission to come here?" Kyojuro asked.
Yes." Tanjiro nodded. "We were given a message from a crow that casualties on this train were rising." Tanjiro informed Kyojuro and Natsu.
"So, that's why you're here. I understand." Kyojuro said.
"That's why we're here, as well, Tanjiro." Natsu said.
"Right." Tanjiro looked at Kyojuro. "I have a question for you, Mister Rengoku, sir."
"Oh? A question?"
"Yes. It was about my father. He... was a frail man. And he could perform a Kagura Dance in a freezing weather." Tanjiro said.
"Wow. That sounds great." Natsu said.
"Good for him!" Kyojuro replied as he complimented Tanjuro Kamado.
Tanjiro grunted. "And then..."
Natsu and Kyojuro leaned their heads closer to Tanjiro.
"Hinokami Kagura... the dance that I found myself doing... just like my father used to." Tanjiro said, then thought back when he fought Rui, the Lower Moon Five Demon.
"You mean, back when you fought one of the Twelve Kizuki on Mount Natagumo?" Natsu asked.
Tanjiro nodded. "Yes." Tanjiro replied to Natsu, then looked back to Kyojuro. "I was hoping that you would know of it, Mister Rengoku, sir."
A moment of silence occurred for a minute. "I do!" Kyojuro yelled.
Tanjiro gasped, surprisingly. "Wait, really?"
"But, I don't. I have never heard of that dance. Not once. Your father taking this Kagura is very commendable. There is nothing more to say about it." Kyojuro said while smiling.
"I saw the dance, once! Tanjiro used it against the one of the Twelve Kizuki back on that mountain! You should've seen it, bro. Tanjiro was incredible! Tanjiro turned his Water Breathing into golden fire! I was so amazed by it!" Natsu commented.
"Well, in that case... you should also become my Tsuguko! I will also look after you!" Kyojuro told Tanjiro.
"N-not so fast!" Tanjiro stuttered after listening to Kyojuro.
Natsu hung his head downward and silently pouted. 'But, bro. I wanted to be your one and only Tsuguko...'
Zenitsu looked over at Kyojuro with no comment.
"Flame Breathing has a long history. A Hashira of both Flame and Water had always existed." Kyojuro begun to explain the history of Breathing Elements. "Flame. Water. Wind. Stone and Thunder are the five Breathing fundamentals. All other techniques branched off from those five." Kyojuro then looked at Tanjiro. "Tell me, Kamitsuchi. What color is your Nichirin sword?"
"What? My name is Kamado! And my sword is black." Tanjiro pouted.
"Hey, your Nichirin sword is black, just like mine!" Natsu noted.
"How unfortunate!" Kyojuro laughed.
"Why do you say that?" Tanjiro asked.
"I have yet to see a Demon Slayer with a black sword become a Hashira." Kyojuro said.
"That's why I'm going to be the first, Tanjiro. And when I do, I'm going to be the first Hashira with a black Nichirin sword." Natsu smiled at Tanjiro.
"That's great. I hope you-"
"Also, I hear that they don't have a clue what style to master. Maybe, I can train you as well!" Kyojuro said, proudly and bold.
"Maybe, later." Tanjiro rejected Kyojuro's offer.
Five Minutes Later
Natsu looked around in the train car he was in, while sitting next to Kyojuro. A bandaged Zenitsu did whatever he could to stop Inosuke from jumping out of the train.
Suddenly, a man dressed in a black Mugen Train conductor uniform had opened the door with a small plier puncher in his hand.
"Ticket, please?" The Train Conductor asked.
"Oh, sure." Tanjiro said as he passed his ticket to the Mugen Train employer.
"Here's mine." Natsu said after the Train Conductor punched Tanjiro's ticket. After punching Natsu's ticket, the Mugen Train Employer then punched Kyojuro's, Zenitsu's and Inosuke's tickets one after the other. A minute later, the lights begun to buzz in and out.
"What's wrong with the lights?" Natsu asked as he stared at the lights.
Kyojuro closed his eyes, temporarily. 'A demon has boarded itself on this train.'
Tanjiro gasped as he caught a whiff of a demonic scent. 'That scent...'
"Thank you so much..." The Train Conductor said in a depressing tone. His head nearly hung down and his blue eyes were filled with emptiness.
"Pardon my Nichirin sword, Conductor. But there is a reason, why I am on this train. Please keep at a safe distance." Kyojuro said as he got up on his feet and faced the door.
Within a minute, the lights kept buzzing on and off, until a eight-foot tall gray-skinned and muscular demon with multiple demonic eyes and teeth appeared. It growled as it raised its head. The civilians who were near the demon had gasped and screamed in fear.
Zenitsu yelped as he heard a growling noise.
Tanjiro gasped, then reached for his Nichirin sword. But was stopped by Natsu Rengoku.
"Let bro have this." Natsu said with confidence.
Tanjiro looked at Natsu in surprise, then looked over at Kyojuro's backside which was in front of him.
"My, my, you're big." Kyojuro commented on the demon's size. Did you use a Blood Demon Art? Know this. If you harm the innocent... I will make sure you disintegrate for good... with my fiery red Nichirin sword!" Kyojuro withdrew his red Nichirin sword from his sheath.
The eight-foot tall demon roared toward Kyojuro. Causing a burst of wind in his direction. The only ones who didn't flinch as the wind burst was Kyojuro and Natsu.
'Flame Breathing. Forst Form...' Kyojuro had taken a fighting stance and his Nichirin sword then coated itself with flames.
'Do it, brother.' Natsu smiled.
The eight-foot tall demon then charged at Kyojuro. And within a second, Kyojuro then dashed toward the demon, passed its claws and decapitated its head in one simple slash.
'Flame Strike!' Kyojuro chanted before crashing through the door. Many people turned their heads as Kyojuro slid and landed on his feet.
Meanwhile, Natsu, Tanjiro, Inosuke and Zenitsu were in the room Kyojuro had just left and they had just witnessed the eight-foot tall demon's body burst into flesh-like confetti.
"Amazing. He killed that demon with a single slice." Tanjiro noted.
'Bro really is amazing.' Natsu smiled, then looked at Tanjiro. 'Oh, yeah. Neither Tanjiro, nor Zenitsu ever saw bro fight, before.'
Kyojuro looked at the door ahead of him, while civilians gasped at what they had just seen. "There's still one more demon." He then looked at Natsu and the others. "You four. Come with me." Kyojuro ordered Natsu and the other Demon Slayers, then ran toward the demon's destination.
"You got it!" Kyojuro passed Tanjiro and ran after Kyojuro.
"All right!" Inosuke yelled out of excitement, then ran after Kyojuro.
"Mmph!" Tanjiro grunted, then grabbed Zenitsu's hand and they ran after Kyojuro.
One Minute Later
Natsu and the others had caught up with Kyojuro and met a tall and skinny green-skinned four-eyed demon with purple markings on its body. Many passengers fled to the rear of the Mugen Train. All except one man in a black kimono, who felt trapped and cornered by the demon.
"You will not lay a drop of saliva on him!" Kyojuro said, catching its attention.
Natsu, Kyojuro and Inosuke then stood between Kyojuro and the demon. Leaving Zenitsu to hide behind one of the seats.
Inosuke saw the demon cracking its body joints. "All right! First come, fir-"
"Stand aside, boys. Its opponent is me." Kyojuro said stopping Inosuke from charging. Tanjiro and Inosuke then took a few steps back behind Kyojuro after listening. "Natsu." Kyojuro had called.
"Bro?" Natsu responded.
"Do you see that man, up there?" Kyojuro asked as he looked at the cornered civilian.
"Yes!" Natsu replied as he easily saw a cowering man in a black kimono.
"Do you remember what I taught you?" Kyojuro asked.
It took a few seconds for Natsu to think and answer, then a glowing firefly had shined over his head. "Yes! If you see a civilian or innocent person that was being cornered or attacked by a demon, you make sure they get to safety, before attacking!"
"That's right!" Kyojuro aimed his blade toward the demon's neck. "I'll take care of the demon, while you save the hostage! Ready?"
Natsu stared directly at the civilian. "I'm ready!"
"Go!" Kyojuro yelled as he dashed toward the demon in close range, then gripped his hilt. 'Flame Breathing. Second Form...' As the demon tried to grab Kyojuro, Kyojuro then slashed upwards, decapitating the demon with his Flame Breathing technique. 'Rising Scorching Sun!'
"Gotcha!" Natsu grabbed the civilian man and carried him on his back, then jumped back to where Tanjiro and the others were.
The demon danced around without a head for twelve seconds before finally collapsing and evaporating in front of Kyojuro.
"You're safe now, mister." Natsu said.
"Thank you very much." The man bowed his head to Natsu, before panicking while running.
Tanjiro stared at Kyojuro with amazement. "That was totally amazing! Please, let me be your Tsuguko!" Tanjiro begged while praising Kyojuro.
"Very well, then. I will also make you a fine swordsmen." Kyojuro approved of Tanjiro's request.
"I wanna join!" Inosuke yelled in excitement.
"Mmph!" Zenitsu muffled in excitement.
"I will be glad to take you all in." Kyojuro replied to Inosuke and Zenitsu.
"Thank you so much, big bro! You're awesome!" Tanjiro Kamado, Zenitsu Agatsuma and Inosuke Hashibira floated around Kyojuro like fish swimming in water.
Kyojuro proudly laughed.
'That's not fair! Why do they have to hog bro like that?' Kyojuro pouted in the corner, feeling jealous.
Four Minutes Later
The Five Demon Slayers such as the Rengoku Brothers, Tanjiro Kamado, Zenitsu Agatsuma and Inosuke Hashibara had all fallen asleep in seats, soundly. Kyojuro and Natsu sat in the same seat and Natsu leaned his head on Kyouro's shoulder. Tanjiro sat on a different seat with his brown rectangular boxes next to him. With Nezuko inside of it. Inosuke and Zenitsu sat in another seat together with Inosuke lying across a bandaged Zenitsu.
Meanwhile, a demonic amputated talking hand had incapacitated the Mugen Train's conductor with his Blood Demon Art. It had markings of Lower One on it and a single cerulean eye on it. This hand belonged to Enmu, one of the Twelve Kizuki and remaining Lower Moon demon.
"Pardon me." A girl in a green kimono called upon Enmu's left hand. "What would you like from us?"
Enmu's hand smiled at the four teenagers, then begun explaining what was happening.
Meanwhile as the Demon Slayers kept sleeping... Natsu Rengoku suddenly sneezed in his sleep.
The Beginning.