Yuji stares at the temple-like construct in his mindscape.

"Hmm… so this is the inheritance of the Kura clan."

He scrutinizes the temple. Several root-like structures protrude from the temple and lay their foundation within the mindscape of Yuji.

"This must be because of the seal on my body. If I didn't have access to my mindscape, then I would directly wake up inside the temple. But thanks to Nawaki's grandma; I can access my mindscape and get a grasp of the situation. Still, that old lady is very scary, and this…"

Yuji turns his attention to the giant black obsidian crystal behind his soul.

"… this obsidian is even scarier. It almost ripped out the soul of the Nawaki's grandma from her body." Yuji shakes his head and takes firm footsteps towards the temple.

"I was one of the strongest assassins in my previous life. And the Kura clan is a clan of assassins. I wonder what surprise awaits me ahead."

Yuji pushes open the door of the temple and steps into the darkness.

-----------------------

The next day in the morning,

"Have Yuji awoken yet?" Minato enquires with worry.

"Let me see!" Tsunade measures Yuji's breathing and pulse.

"His breathing is stable and not erratic like before. He might wake up in a few minutes."

Augh…

Yuji clutches his forehead and slowly opens his eyes. He groans slightly and looks around.

"Where am I?"

"YUJI!"

Minato jumps in front of him. Tsunade's expression turns grim. She silently infuses some chakra in her hands, ready to take action at any moment.

"Thank god, you are alright!" Minato heaves a sigh of relief.

"Minato!" Yuji notices Tsunade and Nawaki standing beside Minato.

"Nawaki, Tsunade-san… augh…" Yuji clutches his forehead.

"Where am I? And what's going on? I was unlocking my chakra and then I… I passed out. I… I can't remember anything after that."

Yuji shakes his head.

"What happened to me?"

'Hmm…' Tsunade scrutinizes Yuji's facial expressions.

'He doesn't seem to be lying. Looks like he has no recollection of the events after losing consciousness. This might be a good sign.'

"Looks like you are fine now. You passed out when I taught you how to unlock your chakra. You were asleep for 10 hours." Tsunade informs him.

"That long!" Yuji gasps.

"Mm… we were worried about you. It was kind of my fault for dragging you here like this. But everything turned out well, so it's fine!" Nawaki waves his hand in dismissal.

"So, did you unlock your chakra?" All of them curiously ask him.

"I am not sure! But I will give it a shot." Yuji closes his eyes and follows the chakra circulation pathway from his memories.

"Look!" A small wisp of dark black chakra appears on his fingertips. Yuji flicks his hand and the chakra wisp dissipates into the air.

"Oh! That's quite good." Tsunade nods in approval.

Stolen content warning: this tale belongs on Royal Road. Report any occurrences elsewhere.

"You seem to have a good amount of chakra control to consciously release your chakra outside your body. Releasing chakra outside the body is the first step to learning Ninjutsu. You still have a lot to learn, but given your talent, I am sure you lot will be fine." Tsunade smiles at them.

'Still, I have never seen or heard of such a pitch-black chakra. Perhaps the chakra nature test might reveal their chakra nature.'

"Looks like all of you have unlocked your chakra. So, the next step is to test the nature of your chakra."

Swish…

Tsunade waves her hand and two chakra paper strips appear in her hands.

"I have already tested the chakra nature of Nawaki and Kushina."

"I have dual elements of Earth and Water, hehe!" Nawaki proudly scratches his nose.

"I also have the dual nature of wind and water release, Dattebano!" Kushina puffs out her chest.

"Alright, let's check Minato-kun's chakra nature first." Tsunade hands over the chakra paper to Minato.

"Circulate your chakra through your body and try to concentrate a bit of it on the chakra paper. It will reveal your chakra nature. If the chakra paper disintegrates into dust, then you have earth nature. If it splits in half, then you have wind nature.

If the chakra paper crumples, then you have a lighting nature. If the chakra paper gets wet, then you have water release and lastly, if the chakra paper catches fire, then you have fire release." Tsunade explains the details to them.

Minato grabs the chakra paper. He closes his eyes and focuses his chakra on the chakra paper.

A few seconds later,

Swish… Bzzt…

The chakra paper splits in half and both halves crumple.

"Oh! That's pretty good." Tsunade is slightly surprised.

"Erm… what's my chakra nature? The paper split in half and crumpled. So, does this mean I have wind and lightning chakra nature?" Minato asks with slight hesitation.

"Yes, you have dual chakra nature of wind and lightning."

"Woah! I knew it. Minato was also as amazing as me." Nawaki makes a smug expression.

Hehe…

Minato chuckles and scratches his head.

"Now, it's your turn." Tsunade hands over another chakra paper to Yuji.

"Alright, I will give it a shot."

Yuji closes his eyes and focuses his chakra on the chakra paper.

'I am also quite curious about the nature of my pitch-black chakra. Minato and the rest are prodigies with dual elemental chakra nature. So, what about me?'

A wisp of dark black chakra seeps into the chakra paper from Yuji's fingers.

The chakra paper turns splits in half. One-half turns black and the other half turns white.

"Erm… what's going on?" Confusion appears on everyone's faces.

"The paper split in half, so he has wind chakra nature for sure. But what about the black-and-white part?" Kushina curiously stares at the chakra paper.

"Even I am not sure about it." Tsunade shakes her head.

"This is my first time observing such a phenomenon."

"Try infusing your chakra into this!"

Mito wobbles out of an adjacent room and tosses a scroll toward Yuji.

Yuji curiously grabs the scroll.

"What's this scroll, grandma?" Nawaki and Kushina question her.

"Hoho… it's a rare chakra scroll to test the non-elemental affinities of the body."

"Non-elemental affinities of the body?!" Everyone's confusion deepens.

"Everyone person, be it a shinobi or a civilian, possesses chakra in their body. This chakra circulates through the chakra pathway system in the body. There are only a handful of people who don't have a chakra system in their bodies. Such people tend to die at a young age since their bodies can't handle the chakra radiation from nature.

Now, for the people with the chakra system. There are several checkpoints in one's body. These checkpoints are called tenketsu points. Shinobis can absorb and release chakra from these points. Most civilians and low-level shinobis have faulty tenketsu points and thus their chakra pathway systems are broken or incomplete. Such people can't circulate their chakra efficiently." Mito explains the details of the chakra to everyone.

"Now chakra itself is a type of energy. It's a combination of physical and spiritual energy. Now here comes the nature transformation of chakra in the play. The spiritual energy of the chakra is responsible for the five-elemental transformation of Fire, Water, Wind, Earth, and Lightning. Other than these five elemental transformations, there are two other non-elemental transformations of Yin and Yang. These two transformations are a result of the physical aspect of the chakra.

Since elemental transformations are a result of spiritual energy, every person can master all five chakra transformations with enough practice. However, the two non-elemental chakra natures are an aspect of the body and thus are bound to a person's body. Unless someone tempers with their body, it's impossible to acquire a non-elemental chakra nature. However, every person has a single non-elemental chakra nature by their birth." Mito turns her attention to Yuji.

"Now for little Yuji here…"

Yuji understands her signal and opens the scroll. There is a single seal in the center of the scroll.

"Place your hand on the seal!" Mito instructs him.

"Relax your body and infuse your chakra and a drop of blood in this scroll."

"Alright!"

Yuji bites his thumb and drips blood on the scroll. He places his hand on the scroll and closes his eyes to infuse his chakra.

Fwoosh…

A few seconds later, a bright black and Tai-chi symbol forms on the scroll. The tai chi symbol slowly revolves around the scroll.

"As I expected!" Mito and Tsunade nod in understanding.

"WHAT?!" Nawaki, Minato, and Kushina curiously turn to them for answers.

"Yuji-Kun is a rare case with very strong affinities for both Yin and Yang Release."

"Wow! Amazing, Yuji!" Nawaki gives a thumbs-up to Yuji.

"Umm… hehe… I don't quite understand it. But it sounds amazing." Yuji slightly curls his lips.

"Me too! Me too! I also want to test my non-elemental nature." Kushina curiously hops towards the scroll.