A Cook, A Doctor, A Ghost and A Ronin.

Haki

One Week Later, Morning.....

After one week being detained inside Butterfly Mansion due to his injuries, he is finally fully recovered from his injuries short after. He could stand up normally and could walk with his two feet just fine. He also regained his strength back at the point he could carry Kiyo.

But after resting for quite a while, a new problems make itself known. He is nowhere hear to his actual strength. His flexibility also had wore off. He can't stretch like he used to do. It's a bit annoying for him.

"Urghh! How frustrating! As expected, my physical is slow to return! I can't stretch out flat like I used to!" Tanjiro could be seen stretching himself with the help of Sumi pushing him while he's stretching.

"Cheer up Tanjiro! I'm sure that you'll return back to your actual strength! You might be even stronger than back then!" Sumi cheered him up, telling him that it's okay. 

"Thanks. I decided to stay here for a while until I regained my strength back. Is it okay for me to stay here a little while longer?" Tanjiro requested that he could stay in Butterfly Mansion a little while longer than before. He wanted to warm-up and train himself before going back in the field.

"Sure! I knew that Shinobu-san will understand. After all, you've fought against an Upper Rank Six after all!" Sumi tells Tanjiro that it's okay. He could stay here until he recovered his strength. He hope he could do so.

"Than-

*Fsssh*

*Creak*

"Says who?" As Tanjiro was about to thanked Sumi, a shadow behind the shoji appeared  while a coarse voice interrupt him. The voice sounds rather displeased. Tanjiro is familiar with this voice. The atmosphere suddenly turned dark with clouds covering the entirety of Butterfly Mansion. Thunder started to echoed throughout the sky.

*Krakoom!*

"I make myself clear again. Says who?" The shoji slowly slides to the left. Revealing a tall figure that wears a distinctive fluffy black and white polka-dot hat. The face of that man is extremely scary that Sumi was about to cry.

"L-L-Law san!" Tanjiro is yet again surprised by Law's sudden arrival. Law could be seen carrying his cursed Sword with him.

"I told you before right? We'll start continue the training right away. Notified Hashibira-ya and Agatsuma-ya to regroup." After telling Tanjiro that he still needs to train, Law turned his back away.

"To where?" Tanjiro asked for a specific location.

"Same place. I'll give you 30 minutes. If you can't make it,  you know what will happen, do you?" Law gave Tanjiro a deadly stare, highlighting that Tanjiro wouldn't want to know what happen if they're late. Tanjiro gulped his saliva.

As Law disappeared from his line of sight, probably using his ability, Tanjiro dashed straight towards Insouke and Zenitsu to tell them about the alarming news he'd just received. They can't afford to be late.

"Zenitsu!! Inosuke!!! Emergency!!!" He ran across the Butterflu Mansion to find his two best friends. He looks pale as a snow. He shouted at the top of his lungs.

20 Minutes Later...

"Huff! Huff! Guys! Hurry up, we can't afford to be late!" Tanjiro lead the pack with Inosuke and Zenitsu behind him, sprinting upwards in the direction of the mountain. He seems to be out of breath.

"Don't order me around! Tanjiro!!" Inosuke finally could say Tanjiro's name properly. He started to race Tanjiro and slowly starts to outpace the red-haired. With a smug look on his face, Inosuke takes the lead while sprinting faster than before.

"Why can't I just leave?! I don't want to go and train!! He's scary! He almost killed me last time!" Zenitsu complained. Originally, he didn't want to go. But he was carried by Inosuke. Since he doesn't want to be left alone, he decided to go along. Knowing fully well of the risk.

"What choice do we have? We will only get worse if we thought of dipping out!" Tanjiro reminded Zenitsu of the consequences. They did come late once and they are greeted with landmines. Tanjiro never wanted to found out what happens if they quit.

"Arghh! Why do we have to do this?!" Zenitsu cursed his luck and his friend's idiotic ideas on including himself in this stupid training session.

"I'm not going to lie, his training worked! I got stronger than before!" Insouke exclaimed. Law's extreme physical training proved to be quite effective. Tanjiro could actually go on toe to toe with Upper Rank 6 all by himself. 

All of them sprint until they could see a clear ground amongst the heavy thick alpine forest. Alpine trees could be seen everywhere here. They could see a man waiting for them at the end, munching on peaches.

All of them stopped. They've arrived early. They took few deep breaths since they've been running non-stop from Butterfly Mansion towards here. Law throws the peach that he's eating and approach the trio.

"10 minutes left. You guys are early today. Splendid." Law praises them for being able to arrive early. 

"What are we going to do today?" Tanjiro immediately asks about their routine and what are they going to spend their time on doing. Zenitsu retorted.

"Wait! Don't tell me! Are we going to spend our time in more training our physical strength?! No! I definitely against that!" Zenitsu is done. He didn't want to do anymore push-ups, lifting heavy boulders, run while carrying boulders anymore. He's tired and might die any soon.

"Relax, we're not going to do any of that right now. We're going to do something that is much more different than we used to do." With a smug on his face, he stood up and walked towards a huge boulder. The size of that boulder is as big as the one Tanjiro had sliced before.

"In fact, we're going to learn about something that would change the tide of battle." Law pulled his hand back. Don't tell me, he's going to punch that boulder?! Tanjiro thought.

*Bam!*

*Crash*

A large, powerful crack appeared on the boulder. A massive damage was inflicted towards the boulder. It looks like it's going to tumble any moments. The trio is in shock. How could he did that like it was nothing? There's not even a single scratch on his hand! It was the first time Inosuke sees such thing.

"Today, we're going to learn about Haki!" Law grinned.