Blue Flame (Rengoku x Reader)

Chapter 3

Due to the fact that Rengoku was still in rehabilitation, you guys decided to train some more at the butterfly mansion. It always jarred you how little Rengoku had been phased by his injuries. Shinobu was right. Rengoku was almost completely healed by now, though others in the Butterfly mansion, who had sustained far less grave injuries, were still bed ridden.

"How do you heal so quickly?" You ask Rengoku one day while the two of you are taking a break from training in the courtyard.

"Total Concentration Breathing!" He exclaims. He looks over at you, "Perfect time to bring this up, my dear student."

He called me dear, your mind reeled. Why did it reel? Not entirely clear.

"Oh- um why?"

"Because it's time for you to start practicing this! I think you've trained far enough so that this should be the next step you take."

Tanjiro, who is doing some strength training nearby yells over at the two of you. "You can do it!" You smile. He really was such a sweet person.

Someone with bright yellow hair burst out of the main mansion, making his way over angrily, his feet stomping up tiny clouds of dust. Tanjiro stops to watch him curiously. "You know him?" You ask Rengoku nervously.

"Of course! He is one of my new students. He must be here to work.", Rengoku responds. "Hello there, Zenitsu!"

"APOLOGIZE!" Zenitsu screams, and the birds fly startled out of the nearby tree. "I worried that you were going to DIE because of your INJURIES from fighting akaza, that really creepy upper moon demon guy. BUT I COME TO FIND OUT THAT YOU NOT ONLY SURVIVED BUT HAVE HAD A GIRL TAKING CARE OF AND FEEDING YOU ON END FOR WEEKS?!?!"

Rengoku looks up, slightly taken aback, surprised. "I- shes just my student." Your heart sinks the tiniest bit at that.

"AWWWWWW" Zenitsu says, smiling sadistically. "Its okay because SHES JUST YOUR STUDENT? ARE YOU STUPID? THAT DOESN'T MAKE IT OKAY AT ALL!!"

Tanjiro runs over, grabbing Zenitsu from behind. "So sorry, Rengoku-san, hes just a little crazy right now."

"It must be-" Tanjiro struggles with Zenitsu, who is wriggling like a fish out of water in his arms. "-his new" He pants lightly. "-medication from shinobu"

"I was just repaying my duty to him." You say, hoping to calm this madman down a bit.

"Really?" Zenitsu says, pausing his fighting to glance at you. "BECAUSE FROM THE SOUND OF THE TWO OF YOUR HEARTS, IT DOESN'T REALLY SEEM LIKE IT"

The sound of...our hearts?

"Zenitsu can hear the sounds of people's hearts and stuff." Tanjiro says, glancing curiously between the two of you. "It helps him detect lying, honesty and sometimes other things."

Zenitsu is still struggling around in Tanjiros arms when Rengoku speaks.

"Enough, Zenitsu." Something about the coolness in his tone makes Zenitsu quiet down.

"Yes, mentor." He says, even though he still looks rather red from his recent yelling bout.

"Go begin strength training with Tanjiro. I will come by later to check your progress.Please quit harassing my student." The both of them bow and walk away. Tanjiro kicks Zenitsu in the shins, making you stifle a giggle.

You spent the next couple hours wondering what he meant.

A/N: Bit of a fluff chapter, I know. More actual content to come I promise! Thank you so much for reading and as usual, please leave me comments I love them sm.