"The ripple." Akai said.
"The... ripple?" Ubuyashiki raised his eyebrow. Akai had arranged his meeting with the master.
"There's this golden energy I can channel with my breathing." Akai explained, taking a deep breath and letting the crackling energy flow through his hand.
"Intriguing." Ubuyashiki leaned forward and commented. "I assumed this was part of your demon art." He muttered.
"I think this is what preceded breathing arts." Akai explained. "I can just barely remember my dad showing me this. I think he wanted to train me in this art. But something went wrong, and he instead decided to raise me normally." Akai said.
"Elaborate. What do you mean by 'went wrong'?" Ubuyashiki asked.
"This." Akai lifted his other hand and heated it, letting it grow red-hot and begin to emit smoke.
"I believe this-" Akai looked to the hand covered in the golden ripple. "-and this-" Akai turned to the hand he had heated. "-use the same energy." Akai said.
"...I don't seem to grasp how these are related." Ubuyashiki rubbed his chin and pondered it.
"As you know, my mother was demon, and my father, a human." Akai began. "Which makes me the only hybrid demon out there." Akai's ego received a slight ego boost in realizing how unique he was. "I believe that I had both the cells of a demon and a human within me, even before Muzan infected me," Akai said. "When the energy is channeled into my demon cells, they heat up, with the only reason I don't die being their rate of regeneration. But when I channel it through my human cells, they manifest as this ripple." Akai said. "I believe the awakening of the ripple was caused by my father's axe. It most likely contained trace amounts of his power, and when it reacted with mine, finally have my cells access to its purified form."
"...You might be on to something here." Ubuyashiki muttered. "Do you have any idea how to manifest this in normal humans?" Ubuyashiki asked.
"Uh..." That was the part Akai was stuck on. "I know for sure that it had something to do with breathing?" He shrugged and chuckled.
"But... that's impossible..." Ubuyashiki paused. "The very concept of our art is based on our breathing. How could no one have manifested this?"
"I have an idea." Akai cut in and Ubuyashiki listened. "As you know, one of my demon arts allowed me to access people's memories."
"...Go on..."
"And Nezuko can already channel my powers." Akai elaborated further.
"...This means..." Ubuyashiki muttered.
"If she uses it, she could access my repressed memories. And we might uncover the secret to this art." Akai finally proposed his solution.
"...Very well. Bring Nezuko here."
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Akai had grabbed Nezuko and taken her to the courtyard outside Ubuyashiki's home, where pillar meetings were held. The pillars were to oversee the event and step in if necessary. Tanjiro and others also came to watch.
"You want me to read your mind?" Nezuko asked.
"Yea, in a way. Do you remember the time I did it to you?" Akai asked.
"I had the brain capacity of a cat at the time, so not really." Nezuko chuckled and rubbed the back of her head.
"Okay, that settles things." Akai stretched and readied himself for the trip.
"You didn't even ask for my consent!" Akai heard Tanjiro yell from behind him.
"LEMME BE MY OWN PERSON, TANJIRO!" Nezuko yelled, making Tanjiro freeze in utter shock and awe.
...
"You ready?" Akai asked Nezuko.
"How does this work again?" Nezuko asked.
"You just gotta make contact with my forehead with the desire to make a connection." Akai explained.
"What do you mean by making a connection?" Nezuko asked, smirking.
"Can you not right now?" Akai growled, feeling Zenitsu's gaze burning into the back of his head.
"Okay, here goes." Nezuko reached forward and tapped Akai on the hea-
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...
...
...
"Woah..." Nezuko awoke in the mind space.
"Here we go..." Akai stood up and dusted himself off.
...
...
...
"THE HELL ARE YOU DOING HERE!?" Akai pointed at Nezuko and yelled.
"What do you mean?" Nezuko raised an eyebrow. "Is this not the right place?"
"This is the right place but that's not the thing that's wrong! Our experiences were supposed to be separate." Akai looked around wildly. "Something's wrong. Or is something right? Did Muzan do this? Did the demon art evolve? Did this happen because we share the demon art?" Akai was feverishly pondering the implications while Nezuko gaped at the giant wall of memories.
"So... This wall is mine..." Nezuko pointed at her wall, which was reasonably sized. "And this one is yours." Nezuko pointed at a mile-long wall, lined with the memories of a man born in a previous millennium.
"Okay... This could still work..." Akai regained his composure and looked at his wall. "We enter the memories by touching the wall. So theoretically, I can ignore yours and enter mine. Okay. We'll enter at the beginning, and search my memories for anything relating to the Golden Ripple. My dad called it Hamon, so be wary of that word too." Akai said.
"So how do we get out?" Nezuko asked.
"Normally, we wake up when we reach the present." Akai explained.
"And if we don't?" Nezuko came up to his side, staring down the wall of memories.
"Let's not go into hypotheticals." Akai ordered. He and Nezuko reached at the same time and made contact with the wall.
--------
Akai awoke to the feeling of warm earth on his back. He sat up and looked around rapidly. He was... he honestly had no idea where he was.
"The hell?" Akai wondered. Had he been woken up? Where did they take him?
"Akai?" Akai turned his head 180 degrees and saw Nezuko get up from the ground.
"...You again." Akai groaned and looked away.
"Why do you seem to not like me?" Nezuko inquired.
"You're one of the only beings alive capable of killing me, with your bare hands no less, and you have a periodic desire to drink me." Akai took a few steps away from her as he surveyed the area. "Wait..." Akai noticed a few buildings spread about the area. The layout... It was... Familiar. "My village..." Akai muttered. It seemed to be smaller than he remembered. Less developed, he assumed. To be expected of the time he was born.
Speaking of which.
Akai could hear the muffled cries somewhere nearby. He walked in the direction of the noise, Nezuko following curiously.
He reached his home. His parents' home, at the time. The cries were closer. Akai opened the door, but his hand went right through.
"So we're intangible in the memories." Akai noted and slipped through the door. Immedietly, the cries grew louder. He zeroed in on the sound and wandered into his parents' room. He couldn't help but smile at the sight in front of him.
His mother laid out on a bed, oh so exhausted after bringing him into the world. The sight of her face nearly brought tears to his eyes, having finally remembered what she looked like. He didn't let her uncanny resemblance to Muzan get to him. This wasn't him. It was his mother. To her side, was his father. He looked younger and had noticeable stubble on his chin and bags under his eyes. The tears now flowed freely. Akai wanted so badly to run over and wrap his arms around his parents. But he knew they couldn't see him, and he couldn't touch them. But, in a way, they were already doing that to him. Nestled in his mother's arms, was him. A newborn. This little bundle of joy had finally calmed, feeling the warm embrace of its mother.
"Wow. You look like a potato." Nezuko muttered.
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Trivia One: Akai was born on a warm summer morning in July.
Trivia Two: Despite being human, Akai was born with two fully-developed canines in his mouth.
Trivia Tree: It was said that Konpeki Suisei did not sleep for three days waiting for his son's arrival.
Trivia Four: Despite being unaware of his arrival, Muzan felt a great disturbance the day Akai was born. Feeling almost as if a great, unknown threat to him had come into existance.