After Nezuko fell asleep, I gesture to others to come here. Of course, I am grabbing Nezuko so that she won't fall on the ground. Tanjiro wanted to say something but I cut him off.

"Tamayo-san, can you check her?" I requested. Yoshiro looked furious because I talked to Tamayo casually.

Slightly confused at my request, Tamayo came near us.

"Tanjiro-san, may I have permission to study your sister's blood?" She looks quite surprised when she saw Nezuko. Tanjiro could only nod with her hasty question.

"Fascinating. Her blood is that of a human. But the fact that her wound closes quickly made me think otherwise. How?" She asked after quickly examining Nezuko's blood.

I made a gesture by guiding down both of my hands to the sides. I am pretty sure there is a rainbow between them, "Magic."

All of them look at me with a deadpan look. Yoshiro, like usual, is furious because I made fun of his Master.

"Well, I turned her back into a human but let her power as oni remains. I don't know if she can still use Blood Demon Art."

Tears are starting to form in Tanjiro's eyes. "Thank you! Thank you very much!"

Seriously, he is a big sis-con isn't he. We then go inside the underground chamber because everything on the ground got destroyed by those two onis from before.

Just about when Tanjiro lay Nezuko on the ground, her eyes immediately open. She quickly gets up which resulted in banging her head toward Tanjiro's.

"Ouch!" That yell came from Nezuko. Tanjiro got a really hard head, huh? Nezuko put her hand on the place where she got hit while looking around.

She quickly latched on to Tanjiro while crying like a baby. "Br- brother!"

She is stuttering. Of course, she would stutter. How many years has it been since she last talked like a human?

Tanjiro also hugged his sister and cried. He had suffered a lot for his sister. I might not admit it but I kind of jealous of their familial love. And it made me miss my family from my previous life.

I quickly pushed that thought out of my mind. We are in a different world now. And my instinct is telling me that I will not be able to return to the world I came from.

I'm not going to lie. The reason I helped Tanjiro is for my own satisfaction. He was one of my two favorite shonen protagonists in my previous life. The other one being Yoh from Shaman King.

Enough said. I am going to sleep. As I was going to lay on the floor, I saw Tamayo and Yoshiro came toward me. I sigh and stand up again.

"Can I help you?" I asked.

"Can you please turn Yoshiro back to human? I am willing to pay anything," she bowed 90 degrees.

I raised my eyebrow. "Anything?"

"Yes, anything." Yoshiro behind her wants to interject something but a look from her stopped him. He has a flower pattern all over him and blushes.

I think for a while. But then, I was like 'F*ck it. I wanna sleep.'

"I will think about it. I will give you an answer tomorrow."

Then I fell asleep. I need to get my priority right.

The next morning, I see Tanjiro and Nezuko both running around the house. Then I went back inside the underground chamber and gave my answer to Tamayo.

"Well, I accept your request. And I will turn both you and Yoshiro back to human."

"I am sensing there is a 'but' coming here."

"I want all of your medical knowledge on human and oni's body," I state my demand.

It might be useless now as I also have Nightingale left to summon. But the medical knowledge of the 500+ years old doctor? I will take it. And I don't know what to demand from her other than that.

I can just turn them back for free. But there is something called give and take. I might give something to my subordinates without wanting anything in return. But she is not my subordinate. So, I demand something from her.

I told them to lay on the floor. I don't want to grab them when they fall asleep after all.

When they fell asleep, I went outside and saw the Kamado duo finished playing around. Both of them come running to me.

"Let me thank you again. Thank you very much!"

Like always, Tanjiro is always full of energy.

"My name is Kamado Nezuko. Brother Tanjiro's little sister. It is nice to meet you. And also thank you for turning me back to human," Nezuko gave me a bow.

"It's alright. I got to see his wonderful breathing style too."

That's right. The style is beautiful. And those water really generates from nowhere! I thought those are some colorful effects to show the viewer where the sword goes.

Then the two of them shoot me question after questions about my country. I answered their questions with the memories I got from this world's identity.

"So, what do westerners do on New Year?" Nezuko asked.

"Hmm… well, we just stay inside and eat something together," I replied.

"That's it?"

"Yes, that's it. And what do you guys do?"

"Well, during New Year, our father offers dance to the Fire God along with our prayers. After our father dies, it was the big brother who dances for the Fire God."

I turn my head toward Tanjiro.

"If possible, can I see the dance, Tanjiro?"

"Of course! After all of those that you have done for us, I wouldn't refuse the request."

"Thank you," I smiled.

Then Tanjiro proceeded to dance the 'Dance of the Fire God'. As expected, Japanese dances are something. They look so graceful. It worth turning Nezuko back to human. Even though I've used her as a guinea pig to test out the extent of .

Something might become different because I've turned Nezuko back into a human. The fight with Ruri is going to be different. I don't mind telling him some of the things I've known about the breathing style.

"That was a good dance, Tanjiro," I said while clapping my hands.

"Really? Hehe, thank you," he sheepishly replies.

"And do you remember what your father said while telling you about the dance?"

My face turns serious and asked him the question.

"He told me that he used the special breathing metho-," he suddenly stops. He is smarter than he lets on.

"Wait, does that mean?" His voice is shaking.

"Yes, Tanjiro. Do you know what I see when you dance? Sword stances. I saw sword stances in that dance, Tanjiro."

I left him to think and went to check on the former onis duo. Both of them already awake.

"I thank you for turning us back into the human. I had already prepared the scrolls and books I've collected and written over the years," Tamayo showed me the scrolls and books. Wow, that's a lot.

"No, you don't need to thank me. It was an exchange after all."

"Nevertheless, thank you." She gave me a smile. I think my face heats up. What the hell? Am I blushing?

Nezuko who came downstairs saw me blushing. She said nothing, get beside me, and pinched me. What the hell wrong with this girl?

[Be careful, host. Nezuko is still underage. If you touch her, the interdimensional police force won't let you off. Even the higher-ups won't be able to stop them if they try to take you in.]

{And I don't intend to touch her. And what the hell, System? Why am I blushing?}

[How old are you right now, host?]

{It's 15 years old. Goddammit. Does that mean, I will get hit by puberty whenever I go on Multiverse Travel?}

[…]

{At least answer! Dammit.}

"Nezuko? It's hurt, you know? It feels like my fleshes are going to be torn apart, you know?" It is starting to get hurt. Nezuko, without minding me, pinched me with her oni strength. I'm starting to think that I was wrong to leave her with her oni power.

"Humph!" She turns her head to the side.

What's up with this girl? It is not love because we just met. Oh! She is on her that time of the month! Finally got the answer, I nod my head sagely.

All of us came back on the ground. Tanjiro is preparing to leave on another mission in the South-East. Nezuko also prepared to leave with him. He tried to stop but his head is not as hard as Nezuko's. A hit on the head is enough to let her leave together with him.

"See you later!" Both Tanjiro and Nezuko said farewell. I also prepared to leave after putting all the books and scrolls into the .

Now, where should I go? I'll just look around the city. And thus, saying farewell to the former onis duo, I get back on the journey.