The Last Poison Blade! Shinobu Kocho x Male Reader!

Infinity Train

You were sitting in the same booth, waiting for the train to depart from the station. "Like i said, as the both of us are present we will have nothing to worry about" Rengoku said as he raised his hand and ordered a bento and waited patiently for it to arrive.
"Do you truly believe that a Demon Moon will appear on the train?" You asked as the bento box was given to Rengoku. "We have no actual way of confirming this, but we know that at least 40 people have disappeared and many of our swordsmen as well."

He then started eating rapidly "Delicious! Delicious!" He started yelling with almost every bite he took which made you wonder if it was actually good, after all it was his favorite meal. You knew he yelled those exact words since you stayed with him a period of time. He was now ordering his 6th box and since it seemed too good you ordered one yourself. "Ah I see that you know what delicious food really is my boy!" He said after you ordered your bento.

When it arrived it looked so good that you couldn't hold yourself and started eating as if you were starving. Unlike Rengoku you didn't say a word while eating but right after finishing your plate you ordered another one right away.
You looked around and noticed that the whole passenger car was staring at the both of you, and out of the corner of your eye you noticed that the trio of strange boys had arrived as well.

You moved all the bento boxes to get cleaned up and tried to get Rengoku's attention but he wouldn't stop yelling how tasty it was. It wasn't until Tanjiro came forward and spoke with Rengoku that he paid attention.
For this you moved to the seat in front of where you were seated so Tanjiro could speak better with Rengoku.
You were surprised by what he said, you never knew that something like that was possible, not only was he applying the dance his father taught him but he also mentioned something about a fire God. Also, Rengoku was very persistent about making him his Tsuguko which made you laugh, especially seeing Tanjiro's reactions since he wasn't used to the way Rengoku socialized.

During this time Inosuke was looking out the window thinking he could beat the train in a race. Zenitsu on the other hand was holding tight onto him so the idiot wouldn't fall out. You truly thought that these boy's, despite being strong, were really weird

As the Train started moving the chauffeur started punching holes in the tickets.
"We need to be well prepared for when the Demon appears" Rengoku said after explaining the whole deal to the Trio. "YOU'RE KIDDING a Demon will appear in this exact train!?! NOOO I WANT TO GET OFF, LET ME OFFF!!!!" Zenitsu started yelling out in desperation, "I will... Look at your tickets..." at this moment the chauffeur approached to punch a hole in your ticket
"What's this?" Tanjiro asked and you patiently explained what the deal was. You, Rengoku and Tanjiro felt it, the presence of the Demons which were hidden.

"Conducter it's dangerous, so stand down! It's an emergency so I would prefer it if you don't ask why I have a sword on me!" Rengoku said as you both quickly got up from your seats with blades ready for battle
The lights started flickering and an enormous muscular Demon appeared right in front of you. The people were obviously frightened and reacted as such.

"Big guy!! Wers you hiding your Blood Demon Techniques!" Rengoku said as he readied his sword. "It was hard to find your presence, however! If you're baring your fangs at innocent people... THE RED FLAME SWORD OF RENGOKU WILL BURN YOU DOWN TO THE BONE!!"
In a single second Rengoku launched himself to the Demon using his first form and killed the Demon in a second.
"There's another one.." He said as you ran already towards that direction. "Follow me!" Rengoku said as he ran to that passenger car too.

You got there before them and noticed a very long legged Demon that was about to injure the passengers. So instead of killing the Demon you hurried to the aid of the passengers. You jumped in the way blocking its attack and then carried the three passengers left to safety. "He's all yours!!" You said as you jumped out of the way. Rengoku then finished it off with a clean slice to the head.
"That was awesome Aniki!! That was amazing swordsmanship! Make me your disciple" Tanjiro yelled out with tears in his eyes.
"Sure thing! I'll make you into a fine swordsman!!" Rengoku said out very proudly
"Me too!" Both Zenitsu and Inosuke yelled out. "I'll look after every single one of you!!" He then laughed even more proud. All three of them were circling him yelling Aniki which made you laugh and felt happy for them.