“Ai! It’s your turn to train!”

“Hm,” Ai raised her head from the two or three books and a notebook lying on the porch under the sun, turning her eyes to see Tanjiro and Konoe sitting on the opposite sides of the table, with numerous cups on the table.

“Oh, rehabilitation training? No, I am good as new,” She grinned, turning her attention to notebooks, only to feel a prickling glare.

She felt sweat on her cheek, even though she tried not to pay attention to that and focus on what she was working on, but she couldn’t ignore it after a few minutes. After all, she knew the other party was persistent and would keep staring at her until necessary.

“Konoe~! I am working right now, and I heal faster because of the Wood Breathing Technique. I have already done it!”

Konoe kept staring at her, maintaining a poker face, without saying anything. And Ai did try to glare back but was defeated in minutes.

She closed the notebooks and books, placing the bookmarks before dragging her legs to her, sitting down in front of her, “Fine, fine. I get it.”

There were many cups of medicine water, and what they had to do was pick it up and throw it on others. The problem was, she wasn’t pure human.

She was a Senju and Vampire Queen since her father was a Vampire Progenitor when she was born, and so she was the Second Generation of a God. Also, she could go out in the sunlight without any worry.

Such physique gave her many passive abilities, like quick recovery and supernatural reflexes.

Even if she tried to dull them down as she focused on Konoe, blocking her every attempt, only seeming to be slightly stronger than Konoe. It wasn’t that Konoe wasn’t strong; instead, there was a chance that she was as strong as Hashira, but with her basic stats and her training, her senses and reflexes were sharper.

After all, this wasn’t the first time she had trained, she had trained to be a Ninja, and she was much stronger than anyone her age. The only one that matched her was her friend, the one who her father had trained since she was six.

She moved her hand, blocking every one of Konoe’s tries when she picked up the cup. Ai used her other hand to pick up the cups, to throw at Konoe, who blocked it a few times but couldn’t.

Rather than splashing the water on her face, Ai touched it against her cheeks, grinning, “See, I am all good now.”

Konoe warily watched her, worried since that was some insane recovery speed.

“You can…use your left hand so well,” Tanjiro watched her with shining eyes, “Should I start using my left hand? Would it help me get stronger?”

“No way,” Ai hastily shook her head, “I wield two swords, so it makes sense that I am ambidextrous. I can use my left hand as well as my right. But you only play using one sword style. It would be helpful, but not enough that you’d waste months on it. Maybe years, depending on your talent.”

Ai jumped to her feet, “Anyway, you two continue. I still have work to do.”

She hurried to the porch, lying down, opening the books and the notebooks she was reading. In the past month, the first thing she did was skim through as many medical books as she could, remembering what she had studied, and it was starting to come back to her.

Then she moved on to her Memory Space, reading her mother’s medical books, journals, and notes. Healing Jutsu helped her the most since she planned to create a Wood Breathing Form that could heal others.

The last month passed before she realized it; the time she had was too short. Even a year or two, she wasn’t sure if that would be enough to cover all the content.

That wasn’t the only thing she had been working on in the past month; she was trying to create Curse Breathing Technique, First From.

As for what to replace the Natural Energy with? Her Nigh-Infinite Life Force.

“That reminds me….” Ai furrowed her brows, thinking about the crippling pain.

In the past month, she realized what that pain was, and it wasn’t from the injuries or beatings. Instead, it was something much more complex.

She, by nature, was an immortal who possessed Nigh-Infinite Lifeforce. Even if she managed to put all that Life Force into Wood Breathing Technique, it wouldn’t make her a Mortal.

She felt the pain that Wooden Breathing held back, the pain of losing Immortality, even if it was only for a moment.

If she had to guess, this technique turned her into a Mortal because she modeled the Technique after Breathing Techniques used by Humans.

The Technique was never meant to be used by an Immortal, so the unexpected drawback.

Although, in the beginning, she had no idea how an Immortal’s Breathing Technique Wood be. Now she had two visible paths and one hopeful path in front of her.

She went back to check the chart, and this time more thoroughly, when she realized that her suspicions were correct.

Last time she saw the Wood Breathing beside Sun Breathing and assumed that it wasn’t below Water and Earth in the chart. When she checked again, she realized that it was there, and that meant that there was something special about Sun Breathing, for it to be on the same level as Curse Breathing Technique that needed a Thousand Year Old Curse, and Wood Breathing Technique that was supposed to be for Immortals.

Using Sun Breathing and Curse Breathing, she might be able to create a Wood Breathing, one that only she could wield.

Other than these two viable ones, there was one hopeful or dreadful possibility that could help her. If a Demon Slayer…were to become a Demon and still use their Breathing Technique, how would it be affected by the Immortality?

Ai turned around to lie on her back at that thought, staring at the sun, “Do Immortal Demons…even need to Breath? Do I…need to Breath?”

She stopped breathing, closed her eyes, and she realized in a while, “I don’t…need to Breath. Maybe I should try that Breathing Technique Constant thing….”

“Wait…” Ai sat up, tilting her head, ‘Wood Breathing takes away my Immortality…because it was made to be used by the Living…by me. Then…why doesn’t other Breathing Styles have the same effect?’

She closed her eyes, not realizing that others were starting to look at her strangely.

‘Was it because all the Styles are derivative of Sun Breathing, the one that is on par with an Immortal’s Wood Breathing? No, it doesn’t make any sense. Even if I assume that the boundary that separates them is different. It’s about Immortality and Mortality. Even if Sun Breathing is strong, it is a Technique used by a Mortal. Even if Immortal’s Breathing Technique weren’t stronger than Sun Breathing, the two would be two different operating systems.’

Ai sighed, ‘Wood Breathing…there is a mystery behind it that I am yet to understand. Something that makes it special….”

She put her finger on the Wood Breathing, the Immortal One beside Sun Breathing, but there was no transfer of Information. Sometimes she wondered why her father gave her the system, and then there were times when she got things like Curse Breathing.

“So many secrets and even more variables. I need to sort out so much of it,” Ai yawned, turning on her stomach and continuing.

The Hashira, the others around her, or even herself didn’t notice the cute chibi figure sitting on her shoulder, watching her work. He stroked her head, “Little girl, you overthink. It’s nothing like that…in fact, it’s something much simpler, much purer. I hope you realize it…when you run out of options.”

The figure disappeared with a smile on his lips, and Ai turned around, looking over her shoulder, “Hm, I think I smelled Dad….”

Two Months Later,

“Hinokami Kagura!! Raging Sun!!” Tanjiro made horizontal slashes; his new and improved blade, the one he got recently, was covered in solar flames.

And his opponent, the girl with golden hair, and green eyes, raised the white broadsword, much calmer than him, “Hinokami Kagura, Raging Sun.”

She two slashed forward, blocking his attacks, using the same attack, but hers was more powerful.

Tanjiro’s felt as if a demon brute hit him; his body got hurled backward, rolling against the ground, dragging before he came to a stop.

He raised his body, looking forward, gasping for breath, “Hah, hah, yours is even stronger than before.”

Ai crouched before him, grinning, “Hehe, I am getting this now. And it’s not about you…I heal faster so I can take more of the side effects. Both of us are missing something about this Breathing Technique….”

Tanjiro sat up and looked at his palm before he made a fist, and a happy grin appeared on his lips, “We can do it. I am sure of it.”

“Hm, is this the Hinokami Kagura that you talked about?”

“Shinobu?!” Ai hastily looked up, seeing Shinobu sitting on the porch, having arrived without sound, “Yes, do you know anything about it?”

Tanjiro didn’t even have the time to become excited when Shinobu shook her head, “No.”

“Although I don’t know, I assume that Flame Hashira must know something about it. Why don’t you ask him?”

“Rengoku? I wanted to see him, but after he had the sword with him for a week, he disappeared without saying anything.”

Shinobu looked down, dazed, “He wasn’t the only one. I must say that Cursed Weapon served as a great motivator. Any Hashira wielded that is more motivated than usual to kill Demons.”

Ai scratched her cheek, “Don’t tell me. I know…better than anyone.”

Tanjiro let out a hollow laugh, “Haha, every Hashira came by here once or twice to take Ai with them and kill a High-Level Demon.”

Ai shrugged, “Rengoku and the Mist Hashira are the only ones that didn’t take me anywhere with them.”

Even as she said that she gave Shinobu a look, who stood up, without caring about the words Ai didn’t say, “I won’t apologize. It’s a good experience for you, going out with Hashira or watching them fight. I will send a crow…you two, take the other two, and meet with the Flame Hashira.”

Ai’s lips twitched, “Do we have to take Zenitsu?”

Shinobu chuckled, with a smile that wasn’t a smile, “Yes, you do.”

“I am sorry,” For some reason, Tanjiro felt he was to blame for Zenitsu’s behavior towards Ai and the other girls.

Ai shook her head, waving her hand as she rushed up to her room to pack her things and clothes. She took the Replica before looking towards the real thing.

She was given this yesterday, even though it wasn’t her turn. Even if she didn’t ask about Hinokami Kagura- No, Sun Breathing, Shinobu, or Kagaya Master planned to send her and Tanjiro.

It didn’t matter; the last she had seen Rengoku, he had a grave expression on his face. Even if it wasn’t anything significant, it might be him being angry over what he saw, and she knew best that anger brought out recklessness, which worried her.

After all, in all the Hashira, after Shinobu, Rengoku was the one she got along with most. Him and Love Hashira.

When Shinobu hugged her head, pulling her forward, she was lost in thought, “Now, take care of yourself on the road.”

Ai was bent forward since her height was taller than what was usual for girls, about 175cm, but she still felt that Shinobu was taller than her for one moment.

She closed her eyes, getting on her knees before burying her face in Shinobu’s stomach, wrapping her hands around her, “You too…don’t be reckless while I am gone.”

Shinobu let out a soft smile, stroking her golden hair, “I’ll try my best not to be.”

“I guess that’s good enough for now,” Ai got up, with her long, yellow kimono sleeves covering her hands as she kept a sword on her back, the other horizontally on her waist.

“Then, Shinobu, Konoe, I am off,” Ai grinned, waving her hand before she turned around and walked as fast as possible. She wasn’t good with sad goodbyes, and she didn’t want this to be one.

She walked fast, nearly running, until she was out of their sight before she leaned against the wall, letting out a long breath, with her bangs covering her eyes, “Ah, damn…I hate these awkward situations.”

She left before Zenitsu, Tanjiro, and Inosuke came and reached the Station that the crow told her about.

“Wow, it’s a train station,” Ai rotated on her heels to get a good view of the station, filled with people waiting for the train.

Konoha didn’t have anything like this, and all she read about trains were in Books that her father read to her. Even though this station was nothing compared to the ones in her Memory Palace, it was real.

She traced the pillar, looking at the bench but not sitting.

“One ticket.”

“Ticket?” Ai tilted her head, and she appeared in front of the ticket counter, looking at the man sitting on the other side of the window, “Wow~~! This is where people buy tickets! One ticket, please!”

The man sitting behind the window looked up, and he went into a daze, staring at the girl with glossy golden hair, and one green eye, with the other one covered by her bangs.

“A foreigner?!” He nearly jumped up since it was rare to see foreigners let alone such a beautiful one. But soon, his eyes went towards the hilts of the swords visible on her back, “Wait, are those swords?”

“Swords?” Ai blinked, confused since she could read the expression on his face. If she had to guess, he was about to call for help from the panicked look in his eyes.

“No! These are my props,” Ai took out the sword, letting it go, arching back to put her palm on the hilt, raising her body until her feet were towards the sky. She gracefully took the other one out while coming down on her feet, performing Hinokami Kagura, not the attacks, but the dance Tanjiro taught her.

Once she started the dance, the man on the ticket counter froze, and the people passing by stopped to stare at her in amazement; some even started clapping long before she ended the dance.

She ended the first dance round, putting the weapons she had been using back on her back, “I have a performance in the next town, and they are not even sharp.”

“I…” The man looked conflicted before he sighed and apologized, “I am sorry.”

“You over there! Why are you carrying those swords?! Who are you?!”

Ai glanced toward the police officers, scratching her cheeks, “A Dancer? I have a performance in the next town?”

“Do you have permission to carry those? If not, then come with us to the station, and give your details. We will make one,” The Officer cautiously said.

“Gee, a girl could try,” Ai turned her head, glancing back as the crowd cleared. Her sight passed through them, looking at the three of her traveling partners, creating a stir of their own, “I guess, till next time.”

Ai chuckled, stepping back, ignoring the officers as they told her to stop. She weaved through the crowd at superhuman speeds, reaching Tanjiro, Inosuke, and Zenitsu, “Run!”

Zenitsu was the first to realize that it was her, and he came running, “Yes, my Queen!”

“What! What?! How dare you run faster than me!” Inosuke hurriedly tried to run faster, being the competitive one. He had been competing with her since he laid eyes on her and heard she defeated one of the Lower Five.

“Hey! You three have swords too?! Wait!”

“Huh? Huh?!” Tanjiro started running too, seeing the officers approaching him, “Why?!”

Ai ran in front of them, laughing joyfully, “Hahaha, sorry!! I got caught!”