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I awoke in a strange temple like structure, made of polished rocks. I wasn't in a bed, or on the ground, but in a pool of viscous liquid, my clothes nowhere to be seen.

Looking over my body, I was surprised to find no injuries on my body. I don't know how long I have been unconscious, but for my injuries to have completely disappeared while I was unconscious, it wasn't a good sign.

"You are finally awake, child."

I turned to the origin of the voice, and spotted a giant bird staring at me with it's round orange eyes. It was an owl. A giant one, several times a human's size.

I couldn't help but ask, "Why bring me here?"

The owl, whose voice was female, and old, said, "You passed Yami Mountain's challenge. Hence, you were given access to Fukuro Temple. What's your name, youngling?"

I had already guessed the answer, but I still sighed in relief when I heard I had passed the challenge. After a moment, I said, "My name is Sukaina Sumichi, Shinobi of the Leaf."

The owl nodded, which was a very odd thing to see an owl do, before saying, "You may call me Elder Nishio."

I rose from the water, not minding my nakedness since I was facing an owl, and I was seven, and bowed to the great owl as I asked, "Forgive me for my rudeness, Elder Nishio, but I wonder, how long have I been unconscious? I have urgent matters to settle back in my world."

Nishio replied with an even voice, "Worry not, child. Only an hour passed since you arrived on Yami Mountain."

I couldn't help but exclaim, "An hour? But my injuries…"

Nishio clarified, "All superficial. Katano did not aim to maim you, and your body has developed impressive healing capacities. Added to the Sacred Water, you healed fast."

I looked down at the viscous water, I could feel it was charged with chakra, and now I knew what it's use was. However, Nishio then added, "The same can not be said about Katano though. She will need at least a week to recover."

I cringed slightly as I apologized, "Sorry about that, I thought she was trying to kill me."

Nishio's voice was almost teasing as she said, "No need to apologize, Sukaina. Katano's claws were coated with a paralysing poison, one made to make your body believe it was really bleeding out."

I slowly nodded, before asking, "Was defeating her the challenge?"

Nishio replied, "Touching her was enough."

Well, in a way I overdid it, but I'm not sure I would have been able to touch her if I didn't use my strongest strike. Speaking of which, I managed to use the Shunshin Slash!

A smile appeared on my lips as I recalled my fight, but I was quickly brought out of it by Elder Nishio who asked, "Are you ready to sign the contract?"

I looked down at my body and asked, "May I ask for some clothes first? It's getting a little chilly, and I'm not too comfortable being naked."

Elder Nishio explained, "Worry not, clothes await you where you will sign the contract."

I don't think she really understood why it bothered me to walk around naked, but she's an owl so that's to be expected.

Still, I was the guest here, and she already told me there were clothes made for me, so I decided to follow her. However, as I took my gaze away from her for literally one second to grab my hitai-ate, which I kept in my pouch, I was shocked to find out she had disappeared.

With a tired sigh, I put my hitai-ate back on my forehead, before walking to the only exit of the room. She wouldn't have just left me here if I couldn't easily find the contract room, right?

Walking out of the room I was in, I found the temple to be much larger than it first seemed, although it was quite fitting for owls of this size. The hallways were all very large and high to allow them to fly, and there were several holes out of which they could fly out of the temple.

I could also see several hallways were all leading to a single room, so I decided to head there.

Once inside, I spotted Elder Nishio, alongside many other owls. They varied in size, but they were all bigger than a normal one. In the center of their formation was a large unrolled scroll. It was blank.

"This is Yami Mountain's Contract Scroll. Sign your name in blood on it, and you shall become the first human who joined Yami Mountain."

Elder Nishio spoke, out of all the people here, she looked like the highest ranked member of Fukuro Temple. I nodded at her and grabbed a ritual knife, before cutting open a small wound on my hand. Finally, I wrote my name on the scroll, before marking my fingerprint below it.

I couldn't really explain it, nor was I even sure I felt it right, but it felt like something changed into the air the moment I signed the scroll. Actually, it wasn't in the air, it was THE air. It felt… lighter.

Strangely, as I moved my arms I did not feel any different, hence why I wasn't sure whether something had actually changed or if my brain was tricking me.

I turned to Elder Nishio, and was about to ask something when a smaller owl, this one was actually the size of a normal owl, came forward and said, "Do you wish to learn our clan's techniques, child?"

This time, it was a male voice, and it felt even older than Elder Nishio's. Knowing size wasn't everything for summons, I bowed slightly and cupped my fists as I said, "I would like to, but I have to go back to my world."

The owl shook his head and said, "You already have an initial grasp on our main technique, Stealth, even though you aren't aware of it yet."

Stealth? I couldn't help but ask, "Was it what the one named Katano used to moved silently?"

The old owl nodded, so I focused on him as he explained, "What do you understand of sound?"

I used knowledge I learned in both my past life and in the academy to reply, "It is a vibration of matter, spreading like a wave."

The old owl chuckled, "It's good you understand this. Are you capable of visualizing this wave?"

I shrugged, illustrations of my past life coming into my mind as I said, "I think so."

The old owl nodded before saying, "Our Stealth technique has several stages of mastery, the first of which is lowering the vibrations in the air to the lowest possible, to the point they become undetectable to most living beings. What do you think comes after that?"

I replied, "Use the waves to trick the enemy?"

The old owl once again chuckled, "Interesting idea, but no. Why don't you take a look around?"

I did as I was told, and was shocked to find out that every owl in the area had disappeared. Moreover, something else had appeared. A mannequin, on which was a beautiful dress made of dark feathers that seemed to merge with the shadows.

The old owl said, "The next stage is to manipulate sound waves to completely negate your own sound, and to turn silent whatever you hold. In combat, this can also be used to shush your opponent's voice."

I approached the mannequin, checking out the outfit as I said, "That is a strong technique, and a beautiful dress."

"It was made with our own feathers. Wearing it will lower the air your body displaces as it moves, thus lowering the sound you make when moving."

I nodded, and without a word starting putting it on. While I did so, the old owl said, "As for the third stage of Stealth, it is used to bend light around you. It doesn't turn you invisible, but much harder to detect."

I turned to him, now fully clothed, but didn't see anything. Still, his voice came from where I looked as he asked, "How is it?"

I focused for a few seconds, before finally spotting a slight trace of the old owl, and said, "Comfier than it looks."

I twirled on myself, and just as promised, I barely made a sound.