If an ordinary person heard such things, their first reaction would probably be to find it absurd, right?
But is it really absurd?
Looking at Roa's serious expression and his golden eyes that resembled molten lava, Tanjiro swallowed hard.
Tanjiro didn't know what to say, so he remained silent.
Roa suddenly said, "Do you know why I walk on the mountain at midnight every night?"
Tanjiro shook his head.
Roa continued, "It's to slay demons and protect your safety."
After saying this, Roa paused for a moment and then continued, "But can you guess what I see every time I slay a demon?"
Tanjiro shook his head, and Roa went on, "They are eating people."
These simple six words brought a tremendous shock to Tanjiro.
His pupils dilated in surprise as Roa continued, "I can easily slay these creatures, but I am just one person, and there are many demons. I can slay one, ten, or even a hundred, but that doesn't mean it's an easy task. I can't protect you all the time; it only takes a moment for someone to be eaten while I'm away or while I'm chopping wood."
Tanjiro remained silent, gripping the axe in his hand tighter.
Roa continued in his steady voice, "For me, I can't truly empathize with this situation, but the biggest victims are not me; they are the ones who are eaten, and their families."
"You can probably feel it too, right? I might sympathize and pity them, but more often, I feel indifferent. Such things happen every moment, and to completely eradicate them, we must defeat the Demon King who stands above all the demons."
Roa looked at Tanjiro expressionlessly and asked, "So, do you know what to do now?"
Tanjiro raised his gaze to meet Roa's, and his once gentle eyes were no longer soft. Just looking into those cold eyes made him want to look away, unable to meet his gaze.
Tanjiro nodded but then shook his head.
He said to Roa, "You want me to learn breathing techniques to deal with those man-eating demons?"
Roa nodded.
Tanjiro continued, "But I can't master them well. Brother Roa, you saw it; not long ago, I was just a boy chopping wood and selling charcoal, still struggling for survival. I can't even take care of myself, and you want me to…"
Roa shook his head and smiled, saying, "Tanjiro, you still don't understand my meaning. I want to teach you breathing techniques so that you can protect your family. Most demons act at night. Although I will be at your home during the day, you will be safe, but what about when I'm not there? Tanjiro, you are the eldest son of your family, and many times you need to bear heavy responsibilities. Only when you have more strength can you find that last glimmer of hope when faced with seemingly desperate choices."
After a pause, Roa continued, "I want you to learn breathing techniques to slay demons, but not for others; it's to slay demons for yourself, for your family."
Tanjiro finally understood. He nodded seriously and said, "Then, I will rely on you, Teacher Roa!"
Roa smiled, feeling that this guy was quite perceptive.
Speaking of Tanjiro, his character was commendable, fitting the archetype of all hot-blooded manga protagonists: kind, innocent, and treating others with a pure heart.
Moreover, Tanjiro had a unique buff—he was not good at lying, and anyone could see through him when he spoke.
Roa had Tanjiro pick up the axe and start chopping trees.
Tanjiro scratched his head in confusion and asked, "Why are we still chopping trees?"
Roa rolled his eyes at Tanjiro, feeling a bit speechless, and said, "If you don't chop trees, how will you support your future living expenses? Not to mention, you and your family can't all join the Demon Slayer Corps, right?"
Hearing this term again, Tanjiro curiously asked, "Brother Roa, are you a member of the Demon Slayer Corps?"
Roa pointed to his uniform and said, "Yes, and I'm quite powerful, um, just like this."
Tanjiro ignored the slightly boastful tone in Roa's voice and continued to ask, "Is the Demon Slayer Corps fighting against demons?"
Roa nodded and said, "It's been going on for hundreds of years, but many times we can't win. At the worst times, we almost faced annihilation at the hands of the Demon King."
Tanjiro exclaimed, "Huh?"
Roa shook his head and chuckled, ruffling Tanjiro's hair. He looked at Tanjiro's rough fingers from years of swinging an axe and said, "Demons are not as easy to deal with as you think. Basically, if you can't kill them, a human of equal strength facing a demon of equal strength will almost certainly end in death."
Hearing this, Tanjiro's expression darkened.
Roa changed his tone, smiling proudly as he said, "But there are always surprises. As long as your strength is strong enough, strong enough that those demons cannot resist, then you can easily sever their heads. For someone as powerful as me, it's easy to cut off their heads. Of course, it takes more effort for the Upper Moons, and as for the Demon King, well, he's a bit difficult to kill."
Tanjiro looked at Roa with admiration and asked, "Can you even deal with the progenitor of demons?"
Roa shook his head and honestly replied, "Not yet, but I should be able to in a few months. Now, let's not talk about that; come with me."
Roa patted Tanjiro's shoulder, took the axe in his hand, and began to breathe in and out.
Roa first demonstrated the technique, then adjusted according to Tanjiro's breathing, finally telling him where he needed to improve.
Watching Tanjiro's state, Roa raised an eyebrow and said, "Tanjiro, maintain your breathing. The more intense the situation, the more stable you need to be. Tanjiro, breathe evenly. No, no, no, not like that. Come on, follow my lead."
Tanjiro looked frustrated, wanting to speak but hesitating. He really wanted to ask if "follow my lead" meant he could be told the key points of the movements.
Roa lightly tapped Tanjiro's forehead and said, "Come on, let's do it again. Inhale, exhale, just like this."
Tanjiro hesitated for a moment. Inhale?
Roa nodded, giving an approving expression.
Tanjiro exhaled.
Roa's previously smiling expression gradually faded.
Tanjiro looked at Roa, feeling somewhat at a loss.
Then inhale again?
Roa's expression turned serious as he said, "You fool, that's wrong."
Roa's fist landed directly on Tanjiro's head, and the impact made a clanging sound as fist met head.
Roa was slightly taken aback, waving his hand and feeling surprisingly good about the impact.
It seemed he could do this a few more times in the future.
Since it was the first time learning breathing techniques, feeling discomfort was normal; it's possible for beginners to choke on a few breaths.
Unexpectedly, Tanjiro had great talent. Although he was just a laggard in learning Thunder Breathing, he was surprisingly well-suited for the Breath of the Sun.
He quickly grasped the basics of the Breath of the Sun, his face lighting up as he said, "Brother Roa, I feel warm all over, as if I have a surge of power."
Roa nodded at Tanjiro and said, "Then, Tanjiro, keep chopping trees like this, continuously changing your breathing, and see where your limits are by the end of the afternoon."
Tanjiro nodded and began to swing the axe, becoming a diligent lumberjack.
After continuously swinging the axe in this high-intensity work, Roa watched Tanjiro closely. Generally speaking, chopping trees would involve some techniques, such as only chopping halfway, leaving an arc, and then applying a bit of force to make the tree fall naturally.
But Roa required Tanjiro to not cut corners, to chop all the way through, and to judge Tanjiro's limits based on the size of each tree.
Of course, this was just a rough estimate. Later, Roa would go to the Demon Slayer Corps and borrow a few wooden swords to throw to Tanjiro, training him through combat.
Chopping trees was exhausting, especially with Roa's demanding standards. Soon, Tanjiro was drenched in sweat.
He had only just touched the threshold of the Breath of the Sun; he wasn't even at the entry level yet. His increased stamina was limited.
Breathing techniques could only be mastered through practice, especially in combat, where progress could be rapid.
Roa only nodded at Tanjiro when he was panting heavily.
Tanjiro sighed in relief and instinctively wanted to drop the axe, feeling as if it weighed a thousand pounds.
But Roa changed the subject, recalling what his instructor had said during military training in his past life.
Roa leaned in close to Tanjiro and said, "Don't rush to rest yet. Hold on a little longer; you can do it, right?"
Tanjiro's face was filled with distress as he looked at his arms, which he could barely lift, and weakly said, "Brother Roa, I can't do it anymore."
Roa replied sternly, "How can a boy say he can't? Can you hold on for another thirty seconds?"
Tanjiro hesitated for a moment, thought it over, and nodded, saying, "I guess I can?"
Then he picked up the axe again and tried to swing it at the tree a few times, but it felt like he was just scratching the surface.
Before long, thirty seconds passed, and Tanjiro looked at Roa, waiting for him to give the next command.
Roa continued with his expressionless face, saying, "I don't know how much time has passed, so you need to shout it out, Tanjiro. Start from one and count to thirty. Don't go too fast, and make sure your voice is loud. I need to hear you before I let you rest."
Tanjiro stared blankly at Roa, glancing at the axe and then at his arms.
In the end, he could only weakly nod.
What Tanjiro didn't expect was that this was just the beginning.
From now on, whenever there are any issues, Roa will find ways to indirectly extend Tanjiro Kamado's training time.
As for whether he would experience muscle soreness after training, the breathing technique has its own recovery properties. Although the body cannot be completely unaffected, it should be fine by the next day.
After letting Tanjiro rest for half an hour, Roa looked up at the sky and suddenly asked curiously, "How about I show you what a real demon is? I happen to be patrolling this area tonight."
At that moment, Tanjiro Kamado hesitated a bit; he was somewhat worried about his family.
Seeing Tanjiro's indecisive expression, Roa shook his head helplessly but could understand his feelings.
Roa then said, "I've checked this mountain area, and there are basically no demons here. You can rest assured. Not to mention, my perception ability is quite strong. If a demon appears, I will sense it immediately, as long as it's in this mountain area."
To avoid a situation like that of Yoriichi Tsugikuni, where a spring appeared and his own crystal was stolen, Roa decided to use some small tricks.
That would be magic power.
He placed some magic power at the entrance of Tanjiro's home, hidden beneath the surface. As long as a powerful entity approaches, Roa woul be able to detect it.
Magic power is Roa's greatest reliance, and he has been pondering how to use it effectively. He found that as long as the magic power used does not exceed the level of advanced magic, it generally won't be detected by the so-called world will.
As for how to judge whether the released magic power exceeds the limit, the simplest way is to feel a sense of urgency, as if there is an eye watching you.
Once this feeling arises, just suppress the magic power. However, the magic power used is a bit less each time, and the recovery speed is very slow. This world is not like the world of "Mushoku Tensei," where magic power flows through the air; it is indeed quite troublesome to invoke the four elements of wind, fire, water, and earth.
However, while the four types of magic are affected, Roa's magic sword has no issues at all.
But even though there are no issues, he can only wrap the magic power around the Nichirin Sword, giving it a magical enhancement.
A complete magic sword is something that, if used, would warrant a title.
So, it is better to use the powers defined by a world in that world.
When Tanjiro finished cutting the fallen tree and placed it into a bamboo basket, filling it to the brim, he smiled at Roa and said, "Brother Roa, let's get going."
Turning around, he saw that Roa had filled a bamboo basket behind him with branches and trunks.
Tanjiro felt a bit embarrassed and said, "Brother Roa, this is clearly my job. I feel a bit bad about it."
Roa rolled his eyes at him and said, "Let's go, it's just a little help."
The two then walked along the path up the mountain.
By the time they reached home, it was already afternoon.
The evening glow shone through the forest, and the remnants of the sunset illuminated the trees. At this time, Tanjiro's mother, Kie Kamado, had already prepared dinner, waiting for the two to arrive.
This dinner was quite abundant, even more than lunch, and Roa had a hearty meal.
After dinner, Roa turned his gaze to Tanjiro and asked, "Are you really not going to come with me to take a look?"
What Roa meant by "take a look" was, of course, at the demons.
For a qualified demon slayer, facing these things is inevitable.
Tanjiro Kamado still hesitated, his gaze drifting between his smiling mother and sister. Roa understood his hesitation and sighed helplessly, saying, "I'm asking if, if they really come, can you protect your family?"
Roa's voice was not loud, and Kie was too far away to hear the conversation between Roa and Tanjiro.
Tanjiro fell into silence; he couldn't find an answer. This question was inherently unanswerable.
Roa assured Tanjiro, "Your family is my family. I have already regarded Nezuko and the others as my sisters. If anything happens to them, I won't feel good either. So, please trust me. If there is a problem, I will come to help immediately, okay?"
Tanjiro sighed and nodded in the end.
Roa smiled and patted Tanjiro's head, calling out to Kie inside the house, "Madam, I'm taking Tanjiro to see the world."
Kie, who was resting in the inner room, looked a bit strange. She opened her beautiful eyes and scrutinized Roa, asking curiously, "See the world?"
Roa realized he had misspoken, cleared his throat, and explained, "I mean to take him on patrol, to teach him how to deal with beasts. After all, Tanjiro is becoming a man now and has to face many things."
Kie lightly responded with an "oh," then turned her gaze to Tanjiro, hesitatingly asking, "Tanjiro, do you want to go?"
Tanjiro nodded, and Kie didn't say anything more, but she did make a request.
"Don't go too far, okay? It's not safe at night. I've been hearing news about people going missing lately."
Roa patted the Nichirin Sword at his waist and smiled, "With me around, there won't be any problems."
Kie nodded and continued to play with the children.
However, a weak voice came from behind Tanjiro. It was Hanako Kamado, who looked at Roa and said, "Um, can I go too?"
Hearing this, Kie stood up, directly pulled Hanako over, and said angrily, "What are you doing running out at this late hour? You can't go."
Hanako could only nod, looking reluctantly at Tanjiro.
Roa smiled at Tanjiro and said, "Your sister really clings to you."
Tanjiro showed a helpless expression, walked over to Hanako, reached out to pat her head, and whispered to her, "Be good, I'll be back soon. Next time I go up the mountain, I'll bring you your favorite snacks, okay?"
Hearing about food, Hanako's eyes lit up. Although she still looked reluctant, she obediently nodded.
As they prepared to leave, Roa reminded, "Remember to turn off the lights. The oil lamps will attract some strange things."
Kie told the two, "Remember to come back early."