Steroid Breathing

[Seiji's POV]

After we had a nice conversation while drinking tea, Rengoku decided to resume his training. He left me and Mitsuri alone so that we could spend time together but instead of doing so, I brought Mitsuri outside to train her.

If she was going to become a demon slayer, I would make sure that she was the strongest that she could be. It would not only be a huge help to humanity but most importantly, it would keep her safe.

"I'm going to teach you a breathing style I created myself. It is not a complete breathing style so think of it as training wheels," I said. She had stars in her eyes that told me that she was excited to learn whatever it was I was going to teach her.

She was excited but she raised her hand in question.

I smiled seeing her that, "It's only the two of us Mitsuri, you don't have to raise your hand," I told her, "What is it?"

"Umm, what is a breathing style?"

A realization struck me like lightning and I robotically turned my head to Rengoku who was engrossed in his own physical training.

That guy had not even told her what breathing styles were. Was it really a good idea to leave her with him?

I helplessly shook my head and explained, "Breathing styles are the main tools of a demon slayer. By mastering certain breathing patterns and training your lungs to maximize your intake of oxygen, you can achieve supernatural strength,"

I paused, "Do you understand?"

"...Yes," she tilted her head.

She didn't understand.

Well, I guess we would have to start with the very basic of the basics. Not that I was complaining, teaching her was not a chore at all. She was mine after all, it was the same as training myself.

"Well, let's sit down and practice first shall we," I said and we both sat down in a lotus position. We were facing each other and I grabbed her hand with one hand and I pushed my other hand on her chest.

At first, my hand sank into her soft bosom and she blushed but they stopped when I pressed on her ribs. I acted professionally even though it demanded great self-control.

I felt the rhythmic expansion and contraction of her chest.

My eyes glow purple and I used an X-ray to see her pink healthy lungs. Like the rest of her body, her lungs were exceptionally large and powerful.

With my eyes and her already insane body, it would not be hard to teach her the basics at all. In fact, it would not be hard to get her to the level of a Hashira.

"What I'm about to teach you - like I said - is a breathing style that I created a long time ago. It is the easiest breathing to learn and also the most effective constant breathing," I said and started guiding her through the breathing patterns.

"It's called, steroid breathing,"

Steroid breathing allows your body to fully utilize your muscle capacity and also promotes quick regeneration and growth of the muscles. It was a breathing style that depended heavily on the user's body.

If your body was strong and you were genetically blessed, steroid breathing would work better on you. Like the substance it was named after, it was an enhancement to your body.

So the stronger your body, the stronger the enhancement.

Now imagine the enhancement on someone as special as Mitsuri who had pink muscles that were also 8 times denser than regular humans.

That would be a female version of Gyomei.

And so, I started cooking up a monster in the form of a cute waifu. The result of my effort would not be visible so soon but it was the beginning.

Also, I could rest easy knowing that Steroid Breathing would live on.

....

We spent the entire day training together. Mitsuri was not acting spoiled or anything with me, instead she was quite the opposite.

She was trying her hardest, she put more effort into training with me than she had ever done while she was training with Rengoku - he told me. She did not want to disappoint me so she tried her very best.

That meant progress was quick.

I could see her lungs with my eyes and I could guide her in detail to learn the breathing pattern. When she faced problems or had trouble learning, I would help her by pushing at her chest and forcing the air out of her lungs in the correct pattern.

That was a great help to her as she could feel what the correct way was - she only had to imitate.

She learned Steroid Breathing in no time. Now if she just learned constant breathing, it would greatly aid her in her training and recovery.

Hopefully, she doesn't grow a beard or something.

I would only be able to coach her for a day so I wrote manuals that she could follow and gifted them to her. At the end of our training, it was already dark and we went inside the house, cleaned ourselves and quickly went to bed.

I slept with Mitsuri, much to her giddy joy and embarrassment. I did nothing lewd to her or anything even though she would offer not an ounce of resistance if I pushed myself on her.

I didn't know why or how I did that either.

I guess when you were certain that something was yours, you did not immediately devour it. Instead, you cherish it because you are certain that no one will take it away from you.

But I remember just holding her tightly in my arms and I had one of the best sleep I'd ever had.

I woke up early the next morning before the sun had even risen. Rengoku had also already woken up but Mitsuri was still sleeping peacefully.

I silently got all of my gear and clothes together and with a final kiss on the sleeping Mitsuri, I decided to leave. My next destination was the swordsmith village where I would fix my sword.

"You're leaving? Don't you think you should say goodbye to her?" Rengoku asked when I was about to open the door.

"No, she's better off sleeping," besides, she said she hated goodbyes because it gave her the feeling that we wouldn't see each other again.

"Where are you headed to? Another mission?"

"I will go to the swordsmith village to get my sword fixed," I said and pulled out my chipped sword for him to see. His face immediately turned into shock.

I internally cringed as well when I saw the flawed state of my sword. I always kept it in a pristine and perfect condition, just like myself and my clothes.

Perfect movement also allowed me to make sure I never chipped my sword or damaged it so this was a shocking sight indeed.

"What happened?" he asked.

"It's from the other night when I ran into that demon," I answered, looking away from the ugly sword.

"....."

"You look like you have something to say," I said when I saw the look on his face. I was great at reading people so I knew.

".. It's just, my friend," Rengoku started, his vibrant yellow eyes - like raging fire - locked on mine with concern.

"Please take care of yourself. And make sure no matter what you feel, never let your emotions change you," he said.

"I will keep that in mind,"

"Don't be like my father," he said and that finally pierced his words to my heart.

His father was a man who was controlled and changed by the deep sorrow and sadness he had inside. He became hateful, he became a victim of his trauma and emotions.

I took another look at my sword - a by-product of my hate for that old demon. My rage and hatred had made me do things that I would never do otherwise.

"..."

"Thank you," I flashed a smile at Rengoku. "You are a great friend,"

"Hahahaha!!" he laughed, but making sure it was not too loud. "I try to be,"

He seemed proud that I appreciated his advice, unlike his father who would throw hands for it. Of course, seeing that, he had to add more.

"Keep your heart ablaze Seiji, be warm to your friends and burn your enemies. And make sure you don't burn yourself,"

"Ya ya ya, too much and it's corny. You can keep your ancestors' motto to yourself," I said, slid open the door and left. It was not the first time that he said those phrases, those were written in the Flame Breathing manual.

I could imagine him laughing behind me as I left with a new light in my eyes.

Heh, I still had a lot to learn huh?

The journey was just starting.

..

..

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[Seiji's POV]

I reached the swordsmith village in under a day. The terrain was rough and since it was meant to be in a hidden location, there were many secret routes that I had to tread but I was able to reach the swordsmith village with zero trouble.

I did not waste time and gave my sword to Hanzo who was absolutely shocked when he saw the state it was in. But since it was my first time and I had a good record of maintaining my sword, he did not scold me.

Instead, he gave me my old Odachi and said to wait a few days for my sword to be repaired. It was the sword of a Hashira which was made with the best of the best quality, so even repairing it would take some time.

"I'm sorry for the inconvenience," I said with a bow.

"Don't worry about it, these things happen. But make sure you be careful next time," he said and immediately went to his workshop to fix my sword.

Having accomplished my task, I left the swordsmith village. Although I regret not enjoying the hot springs, I had no time to waste anymore.

With Raven sitting on top of my head, I immediately started getting assignments. I travelled towards the east and cleared any mission that popped up in that direction.

In just two nights, I was able to slay a total of eight demons and complete five assignments. I was not called the most efficient Hashira for nothing.

My eyes which underwent an upgrade while I was tracking the old demon were now even more effective in completing missions. A single glance around the forest and I could easily track any demon.

But on the third day, I slept in the morning and when noon arrived, I continued my travel. I was in the territory of the Water Hashira and just like I hoped, I ran into Giyu while he was on patrol.

A day patrol mostly consisted of the Hashira checking the surroundings to see if there were any traces of a demon left the previous night.

I met with Giyu and we decided to go to a restaurant nearby to have lunch. We ordered miso ramen and enjoyed the meal together.

"I heard that you killed a lower moon again. Thank you for your work," Giyu said before slurping on his noodles.

By the way, it was good manners to slurp the noodles loudly in Japan because it told the chef that you were enjoying them.

I could not hear it but I imagined this to be an annoying tradition for most people.

"It was my pleasure to slaughter them, " I admitted with a shrug while enjoying the soup, "What about you? I heard that you took a new Tsuguko again,"

One difference my existence made was that Giyu was now comfortable in his identity as a Hashira. So he had taken quite a number of Tsukugo even though he had taken none in the anime.

Giyu gave me a nod.

"How long?" I asked with knowing eyes.

"He spent two months with me before he created his own breathing style and left," Giyu said, trying to remain stoic but I could see that he was depressed.

He had been taking many Tsuguko and tried to train them to become his successor but they all left one way or another. Most of them just created their own breathing style instead of mastering Water Breathing.

That was the problem with Water Breathing. It was so versatile that many ended up creating a different variation. Most of the unique breathing styles were derived from water breathing like, flower breathing, insect breathing, oil breathing, ice breathing etc.

"I was hopeful this time because the candidate was very talented. But in the end, he branched out from the Water Breathing line," Giyu said.

"Really? What was his name?"

"Obanai Iguro. He created the Serpent breathing,"

I paused for a second before swallowing my soup loudly, "Obanai? Like the kid with two eye colours?"

"Yes, and don't call him a kid Seiji, he is older than you," he replied.

"How did you know him anyway?" he asked.

"Met him in one of my missions," I said and he nodded, accepting my answer.

That was an interesting piece of news. I never thought that Obanai would be a Tsuguko of Giyu at any point in his life.

I remember in the anime that they had some beef.

"Wait, did you two even get along?" I asked and Giyu was hesitant to answer at first before he said.

"I got along with him,"

I laughed, that was such a sad sentence, Why would nobody become friends with my good boy Giyu? He was so nice!!

Well, maybe his facial expression needed some work. He was too aloof, no one other than me could read him at all.

"So, what rank is he in now?"

"Tsuchinoe," Giyu answered.

Interesting, he should need at least one more year before becoming Hashira. But I couldn't wait to meet him, hopefully, he didn't crush on Mitsuri as he did in canon, lest I crush him.

We enjoyed the rest of our lunch before we separated again. A friend we may be but we had our own duties and responsibility.

The next day, my sword was finally finished and Hanzo came to deliver it to me.

And so the life of the Steroid Hashira continued.

Two months passed

..

..

[IMAGE]

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Author : Don't forget to give me stones. I got a whole cold so this week updates are uncertain but I'll try my best.

Patreon : Emmanuel_Capricorn. We got Seiji video edits and shits now so check it out.