Chapter 16: Training Arc

A week had past in the blink of an eye.

During this week, Akio had told his parents in this world that he was leaving to get a job. He was technically 17, which was old enough to decide some stuff for himself. His parents didn't ask much, but they did seem a little worried. After lying his way through everything, he eventually got permission.

Even if they denied, he would of still left. This wasn't his world nor his real parents. However, they were very reasonable, asking him just to send letters occasionally. Honestly speaking, Akio felt that they were a little... hollow? He wasn't sure how his system works. He simply knows that he inhabits a body that was identical to what he looks like. And whether his parents were created by the system so he can exist in this world, he didn't know.

Furthermore, a few days ago, he had once again killed another demon. Two of them in fact! However, the demons were much slower and weaker than the sadistic one he had killed. He had slaughtered the first one with his skills and wisteria — receiving one point to invest in his stats.

Akio was surprised when the second demon he killed, that was around the same level, didn't give him any points though. Akio felt his system probably gives points when he defeats a new rank of enemies, or perhaps worthy ones?

He wasn't too worried though. If he meets all the important characters in this world, he would get a considerable amount of points. Moreover, he was sure that the stronger the enemies, the more attribute points he gets.

The lower moons and upper moons would definitely give a considerable amount.

Akio still has some unused points. He didn't need to use them at the moment, so he decided to save them for later. He would definitely give an enemy a surprise when he randomly just gets a boost in strength. Akio evilly snickered at this thought.

As for Mitsuri, she was opening up to him more and more. Akio had visited her everyday to spend time with her.

Today, Akio was going to meet up with Rengoku. He had said that he would find him if he finishes his mission, else if a week passes, he would meet up with him at a certain location.

So, with the week quickly passing, Akio had met up with Mitsuri. She had also convinced her parents with her own means. 

They both walked together towards the spot Rengoku will be at. After a while, they both arrived near the entrance of the village. Seeing the man with flame-like hair, Akio knew he was Rengoku instantly.

Rengoku immediately spotted Akio, "It's good to see you, young Komiya! Are you ready?" He spoke with his usual expression.

Akio gave a nod before replying, "I'm ready, Mr Rengoku."

Mitsuri, seeing the person they were supposed to meet, also gave a polite greeting.

"Hm? Who might you be?" Rengoku asked. This was his first time seeing Mitsuri. Furthermore, he didn't expect someone to be accompanying Akio.

Akio introduced Mitsuri, explaining her situation and how she would also like to be a demon slayer.

"You are Akio's fiance? Do you also want to be a demon slayer? It is a very difficult and dangerous job, are you sure?" Rengoku asked. He could see that she indeed has a strong constitution. It wasn't evident, however, his years of training and senses told him so. He wouldn't reject her, but he will definitely warn her about the dangers.

"Yes! I also want to protect the lives of everyone that I care about!" She spoke in a firm voice. She had completely believed in Akio now after seeing Rengoku's appearance. He had the katana that demon slayers had, alongside their unique haori and clothes.

"Very well!" Rengoku exclaimed.

"Follow me!"

...

Akio and Mitsuri followed Rengoku for days. If it weren't for both Akio's and Mitsuri's physique, it may have taken weeks. He had led them to a secluded place in the forest.

"This place should be it." Rengoku remarked. 

Arriving at their destination, Akio noticed that they were at an open space with many trees surrounding them. Looking around, Akio noticed that there were different tools, straw dummys and many other things used for training.

"We will be training here. In the past, I had trained here quite frequently. Food won't be an issue as the animals here can be hunted." Rengoku explained.

"Wow! This place is awesome!" Mitsuri beamed. She seemed very excited.

"Where will we sleep?" Akio asked. Other than the equipment used for training, he didn't notice any place for sleeping.

"Oh? Well, you can find a good spot in the forest! As demon slayers, one should be able to sleep any where!" Rengoku exclaimed.

Akio's eyes twitched a little, however, he immediately composed himself.

"I see."

Mitsuri's happy mood seemed to have been reduced quite drastically though. 

"Hmm, seeing how you two already have a good physique, some steps will have to be removed. Normally, as a demon slayer, you would need a high amount of endurance and resilience. So generally the first part of most demon slayer training is to train your body. But we can take a few detours."

Rengoku pondered a little before speaking, "Very well, I'll explain and teach you two about total concentration breathing and all the flame breathing forms first."

"Total concentration breathing?" Mitsuri was confused. She only has a vague understanding towards demon slayers which was provided by Akio.

"Yes! This is a crucial part in becoming a proficient swordsman! It boosts your natural healing factors, energises your body and spirit whilst releasing your body's entire potential hidden within."

"However, learning this can be extremely difficult. Some can take a few months, others a few years. Total concentration breathing is something you feel. You'll know when you do it correctly." Rengoku explained.

Akio was aware that total concentration breathing is used to increase your blood circulation and heart rate, heating up your body and granting the user supernatural strength.

However, he didn't know how breathing a certain way would achieve that. It would be like trying to figure out the correct path in pitch black darkness.

"Equip yourself with the wooden blades over there." Rengoku pointed.

Akio turned and noticed a wooden rack holding around 10 wooden swords and another rack with tens of broken ones that Rengoku had used and probably shattered during his training.

Picking up the swords, Mitsuri and Akio prepared for Rengoku's teachings.

...

Weeks flowed by quickly.

In three weeks, Akio had gotten accustomed to the training. Mitsuri, however, seemed to be a little troubled, but she persevered. With both Rengoku, and his words of motivation, Mitsuri was enduring well.

Rengoku guided both of them carefully, slowly teaching them the breathing techniques and fixing all of their slight errors in swordsmanship. He was quite amazed at how quickly they learnt.

"Flame breathing is used as a means to adapt to your opponents — like a fire bending endlessly and elegantly. All of these forms will help you in countless unpredictable situations. Some can defend, some can attack, some for movement. It would be your own decision making in the heat of battle that counts." Rengoku spoke.

Both Akio and Mitsuri nodded, as they listened carefully.

They still haven't grasped total concentration breathing, however, their swordsmanship was improving by leaps and bounds, receiving their teacher's acknowledgement.

With their techniques and forms being slowly refined, all that was left was to master total concentration breathing. It was the key to being able to slay demons with ease.

With their swordsmanship, they also trained their lungs, something that would definitely be beneficial when learning how to do constant total concentration breathing.

However, after a few more weeks, Rengoku gave Akio and Mitsuri something.

"You two should wear these. Despite already having a strong physique. It would still be good to condition your entire body so it doesn't collapse under pressure."

"Training vests?" Akio looked at the two bulky yet sleek black shirts. 

"Indeed! Only take them off when you're sleeping or cleaning yourself!" Rengoku spoke.

Receiving the small gift, Rengoku once again began fixing their mistakes.

Holding the weighted vests in his hands, Akio was quite surprised.

It was quite heavy!

It wasn't too noticeable, but it would definitely hinder Akio and Mitsuri's movements despite their strength.

...

With the passage of time, Winter had arrived, casting the world in a layer of white.

The forest that use to have thousands of trees that were verdant green with lively plants that surrounded it had now been completely covered in snow.

A youth with worn down clothes and unkempt hair could be seen jumping from tree to tree. His black hair was quite long and messy, however, his scarlet eyes shone with an inner radiance.

Akio was currently hunting for food, his eyes carefully scanning his surroundings. After a few minutes, he eventually found a few footprints in the snow.

"This should be a boar. Quite a large one at that." He quietly remarked to himself. Akio was currently on hunting duty. Usually, he and Mitsuri took turns hunting.

Around 5 months had past since their training.

Akio had mastered everything extremely quickly. He learnt total concentration breathing in around 2 months. After realising that the phenomenon that happened to him when he invested his points was similar to the feeling of total concentration, he quickly learnt it. Akio thought that maybe his vitality helped him in this regard.

Other than that, he simply honed his swordsmanship with Mitsuri untill she also learns total concentration — both of them lightly sparring with eachother.

In less than 6 months Mitsuri had also managed to learn it.

As Akio was following the tracks, he eventually stumbled upon a massive creature clad in black fur. The creature was quite big for a boar. It was around 150cm in height and nearly 200cm long.

Akio smiled lightly, "Perfect!"

With how much they were training, both he and Mitsuri liked eating. Akio didn't need to eat as much as Mitsuri, but it would still shock many people.

Akio leapt out of the tree and landed onto the snow with a light thud. The sound was immediately heard by the wild boar as it raised its vigilance against the unknown creature behind it. 

Facing off against the boar, Akio wore an indifferent expression. The boar gave off a menacing look and a loud grunt at Akio to warn him, however, he remained motionless and thoughtful.

"Hm, let's do something else." Akio muttered to himself.

Usually, a simple cleave or dismantle was enough for him to acquire food. But Akio wanted to test his swordsmanship today.

Taking a stance, Akio held the handle of his blade and unsheathed his katana. It wasn't anything special. After a few months of training with the wooden swords, they were given real ones to get use to.

Akio released a bit of battle intent which the boar immediately sensed, becoming enraged.

Seeing how Akio wasn't backing off, it deemed him as a threat. The boar didn't think this puny human could do anything to it. Given its size and power, comparing himself to Akio, this boar was a little arrogant. He definitely felt like he could easily squash Akio like a bug.

Giving off a loud grunt, its eyes immediately became bloodshot as it ruthlessly charged at Akio.

The wind slightly howled with its momentum as the boar's figure swiftly arrived before the human in front of it. With each step the creature took, it felt as if the ground was shaking whilst the boar's massive legs stomped into the snow and out.

Akio simply waited patiently with his blade drawn.

Once it was close enough, being around a metre from crashing into his flesh, Akio finally made his move.

Inhaling deeply, a sharp current of air flowed into Akio's lungs. Feeling his lungs expanding and his body quickly heating up, his heart thumped loudly as the blood around his body circulated swiftly.

This was total concentration breathing.

Something that separates the average human in this world to demon slayers that could split boulders into two!

With a casual step to the side, barely evading the blow, Akio nimbly moved his body before twisting his wrists upwards.

A vertical slashed evoked the feeling of flames as a arcing wheel of fire tore through the boar's neck, effortlessly severing it.

Letting out a small breath of cold air, Akio saw the boar's dead body dive into the snow due to its prior momentum.

Akio had used the second form of flame breathing, rising scorching sun, which had easily killed the creature.

As blood leaked from the corpse, dyeing the snow in a scarlet colour, Akio walked up and casually picked up the creature and placed it on his back. He then made his way back to his wooden house.

As he was walking back, he contemplated a little about the breathing techniques. In the anime, apparently the visuals you see when demon slayers attack are fake. Akio realised now that in this world, they aren't necessarily fake. It's just that when attacking, you release all your intent into your techniques. 

This intent manifests into a feeling where the techniques actually give off a supernatural result. If it was truly fake, it wouldn't make sense that people like Zenitsu could move like that in the anime — flying around with ridiculous speeds when fighting the upper and lower moons. Maybe he was just overthinking it. But perhaps when he arrives in a world where there is mana or some kind of energy, the techniques he uses would actually mainifest into reality.

After around half an hour of walking, Akio eventually made it back to a small, shabby looking wooden house. This was something he and Mitsuri created as they didn't think they could sleep outside in the forest or on top of trees. Rengoku didn't really mind that they did this.

Next to the house was a fire that was burning quite intensely, heating up the surroundings. The popping and crackling sounds from the fire mixed with the scent of smoke was something Akio had grown accustomed to.

A lone figure could be seen seated next to the fire, her arms wrapped around her legs.

As the sound of footsteps behind her reached her ear, Mitsuri quickly turned around. "Akio! You're back!"

Returning her greeting, Akio threw the headless boar next to the fire. "Yep, I also got us some food."

Mitsuri stood up and swiftly jumped on Akio, tightly coiling her arms around him. Within six months, Mitsuri was more confident and comfortable around Akio which was a nice change. After their small hug, they eventually prepared the boar.

The scent of charred wood mingled with the tantalizing aroma of roasting boar filled their surroundings.

Akio, his face illuminated by the warm glow of the fire, casually spun the boar, ensuring every inch of the succulent meat was evenly cooked.

As it rotated over the flames, juices sizzled and dripped, sending up plumes of fragrant smoke that enveloped the surroundings in an irresistible fragrance.

Mitsuri eyed the boar with a fixated expression, almost drooling. "Akio, how are you so good at cooking! Everything you make tastes amazing!"

Akio had a satisfied expression. "I learnt a thing or two."

In his first life, due to his solitary lifestyle, he enjoyed cooking quite a lot. However, he never really committed to it, so he wasn't some kind of 5 star chef.

Akio watched the meat slowly caramelizing, the skin crisping to a golden perfection.

Finally, with a satisfied smile, Akio felt that the boar was ready. With swift movements, he carved thick slices of tender meat using his katana.

"Here you go Mitsuri." Akio handed.

With her mouth watering, Mitsuri received the slice from Akio. "Thank you!"

As they savored each mouthful, surrounded by the warmth of the fire and the company of eachother, they eventually devoured the entire boar.

After eating the boar, they were both extremely full. What was a meal for a family of three for a week had been completely devoured by the two in one day.

"That was delicious." Mitsuri sighed with satisfaction.

Akio pondered a little. He definitely could have made it better if he used the ingredients from Earth. But nevertheless, it was quite enjoyable.

Soon, night arrived.

Akio was currently cleaning and polishing his sword. Akio didn't know why, but he quite enjoyed doing this. He wasn't some weapon enthusiast, but taking care of his katana felt like the natural thing to do.

As silence enveloped the forest, with a fire that had greatly dimmed compared to a few hours prior, Mitsuri had a thoughtful expression.

"Akio?" Mitsuri asked

"Yes?" He responded, his attention turning to Mitsuri.

"When do you think our training will be finished?" Mitsuri asked. She had been inside this forest for 6 months which meant she was probably feeling somewhat bored or homesick.

Akio thought a little before responding. "Well, since you've learnt total concentration, I'm sure it's almost over. Maybe when Rengoku comes back from his mission will our training be finished." Akio answered.

"Hmm. Okay!" Mitsuri exclaimed.

...

Akio and Mitsuri didn't have to wait long as Rengoku returned the very next day.

"That is everything I have to teach you!" Rengoku exclaimed to his two students in front of him.

"Now you two would have to finish final selection held in Mount Fujikasane to become official demon slayers." Rengoku spoke with a clear voice.

"Take these. They are swords that are capable of beheading demons. You will need them during final selection."

After those words and his gift to the two, Rengoku simply turned and left. However, after taking a few steps, he suddenly halted.

"Be careful, and return back safely." Rengoku voiced, before disappearing into the snow white forest.

Akio felt a little relieved, his training was finally over, however, he also felt a hint of melancholy. He spent quite a while in this forest. Most of his time was spent with Mitsuri while the two of them practiced and learnt under Rengoku.

Since he was a hashira, Rengoku couldn't guide them everyday. Usually he would teach them and provide ways in which they could improve for a few days before embarking on missions to hunt down demons.

Now they would soon leave for Mount Fujikasane for final selection.

Mitsuri also seemed a little sad, but also extremely excited. She was finally going to leave the forest with Akio!