Yin Seal

"Here you are." Tsunade sat up.

After the Sannin had waited until Jiraiya was feeling better that day, they gathered together again and talked for a long time.

In the end, Orochimaru returned and told Hyuga Ao to go to Tsunade's place the next day.

"Good day, Lady Tsunade."

"Why call me Lady Tsunade? That sounds so formal. Just call me Big Sister Tsunade!"

"All right, Big Sister Tsunade." Hyuga Ao readily went along with it.

Since that day, Tsunade's impression of Hyuga Ao had improved greatly. She directly skipped the observation period she had mentioned earlier and prepared to help Hyuga Ao implant the Yin Seal.

Tsunade led Hyuga Ao to her tent.

"Take it off," Tsunade said.

"Huh?" Hyuga Ao froze for a moment.

Seeing her expression, Tsunade smiled. "Your clothes. The Yin Seal requires drawing an array pattern."

"Oh, oh, oh." Hyuga Ao hurriedly nodded, but as she began undressing, she hesitated again.

Although she was a woman now, neither in this life nor her previous one had she ever undressed in front of another woman.

"You little brat." Tsunade laughed and scolded her. "Go on, take it off. No one's interested in those few ounces of flesh."

Hyuga Ao blushed slightly, then took off her clothes and knelt on the array pattern Tsunade had prepared.

As Tsunade mixed the ink used to draw the array, she ran one hand along Hyuga Ao's smooth back and muttered, "This little brat has pretty good skin."

When faced with an assault by a female lecher, if she couldn't be even more shameless than the other party, Hyuga Ao could only endure it. Still, that touch successfully eased her embarrassment.

"Relax! Sit up straight! Don't move!" Tsunade's expression turned serious as she explained, "The array pattern required for the Yin Seal is extremely complicated. The slightest deviation can lead to a difference of a thousand miles."

"So, while I'm drawing the array pattern, you absolutely cannot move. Understand?"

Hyuga Ao nodded.

After receiving Hyuga Ao's response, Tsunade continued, "Although the Yin Seal only manifests externally as a mark on the forehead, the array pattern actually covers the entire body."

"We'll draw the pattern on your upper body first, then your lower body."

"The Yin Seal is best drawn when someone is young, since that minimizes the workload and means you won't need to shave any body hair."

At this, Tsunade's expression changed slightly, as if she had recalled some painful past.

"Clear your mind! Focus! I'm starting!" Tsunade said solemnly.

Hyuga Ao took a deep breath and slowly relaxed her body.

Seeing her condition, Tsunade nodded in satisfaction and began drawing from Hyuga Ao's forehead.

Hyuga Ao had a Caged Bird mark on her forehead, but that didn't matter. The Caged Bird did not interfere with applying the Yin Seal.

Tsunade placed the tip of her brush against the center of Hyuga Ao's brows and drew downward in one continuous stroke, outlining a facial design.

Hyuga Ao's eyes were half-closed as she controlled her body and prevented it from moving.

When the special ink Tsunade had prepared was drawn onto her skin, Hyuga Ao first felt a cool sensation. Then it slowly began to heat up, eventually reaching a temperature that brought a faint burning pain.

An invisible force seemed to emerge from the array pattern and begin penetrating beneath her skin, drawing out Hyuga Ao's chakra and guiding it through the pattern.

Tsunade's brush never stopped. It slid down along the curve of Hyuga Ao's neck and quickly traveled across her body. Once she had drawn the general outline, Tsunade stopped and reminded her, "Next, the array pattern will heat up, and you'll feel a burning sensation. Endure it, and it'll pass."

After warning Hyuga Ao, Tsunade dipped her brush in more ink and began filling in the details on her front.

Hyuga Ao suddenly felt a chill across her chest, followed by one stroke after another. She couldn't help opening her eyes and glaring reproachfully at Tsunade. Why are you drawing so many lines there?

Without even looking up, Tsunade knew what Hyuga Ao wanted to say. "I'm leaving room for future growth. The Yin Seal will form a network across your entire body. If you have a promising future and it breaks from being too full, that would be bad."

"Okay... all right." Hyuga Ao could barely accept that explanation.

Just as she had accepted it, Hyuga Ao felt another stroke being drawn. A strange sensation surged through her. If she hadn't already mastered Embryonic Breathing and gained firm control over her body, the stimulation would have nearly made her shudder all over.

Hyuga Ao helplessly opened her beautiful eyes and stared at Tsunade again, waiting to see how she would explain it this time.

Tsunade said with a perfectly serious expression, "This stroke is to seal the route and connect the network on your upper body. This is the most suitable spot. It's an intersection."

"Strange. Why didn't she jump up like I did back then?" Tsunade muttered under her breath.

However, Hyuga Ao happened to hear her clearly.

The only part of her body she could move was her eyes, and they filled with helplessness. She simply closed them. Fine, fine. Do whatever you want.

Tsunade smiled, finished the last few strokes on the front of her body, and extended the lines toward her back.

Tsunade dipped her brush in ink again. "The back is the smoothest and most orderly part, so there will be quite a bit to draw there. You'll need to endure it. This ink will raise your body temperature and then engrave the array pattern into your body, like a tattoo."

"Endure what? It's just a little burning sensation." Hyuga Ao couldn't help feeling puzzled.

Hyuga Ao could only be called young for thinking that way. She didn't understand the tricks doctors used.

The array pattern Tsunade had drawn began to heat up. The heat linked with Hyuga Ao's chakra and drove up her body temperature, raising it to nearly fifty degrees.

Hyuga Ao immediately felt dazed and feverish. It was as if she had been placed inside a furnace. If the array pattern hadn't carried her chakra and protected her body, no one could have survived such a temperature.

After a while.

Hyuga Ao collapsed on the ground. The heat from engraving the array pattern had nearly burned her to death.

Tsunade crouched down and patted Hyuga Ao's cheek. "Wake up. Don't tell me you've already passed out."

Hyuga Ao propped herself up and complained in a soft voice, "Big Sister Tsunade, you never told me about this at all!!!"

"Ha ha ha." Tsunade burst out laughing. "I'll definitely tell you next time!"

"All right, all right. You don't need to stand up either. Just lie there like that. I'll finish drawing it and we'll be done."

Hyuga Ao glared at Tsunade. "It won't be like before again, will it?"

"No, no. The network has already been connected, and the array pattern has been engraved. The lower half will be fine."

"All right." Although she didn't entirely believe Tsunade, things had already reached this point. It was impossible to leave halfway through, so Hyuga Ao could only trust Tsunade one last time.

The array pattern on her legs was much simpler. Most of it was on the upper body; the legs only needed the network that collected chakra.

Tsunade quickly finished drawing on her legs. Finally, she sealed the pattern at Hyuga Ao's toes. Once she had connected it through the various acupoints, she put away her brush and stopped.

The final wave of heat traveled along the patterns on her legs and reached her feet, gathering in the acupoints on her soles before flowing back through them to her internal organs.

Hyuga Ao felt a gentle warmth in her internal organs. It was extremely comfortable. By this point, the network throughout her body had been fully connected, and the Yin Seal was mostly complete. Only the final step remained.

Tsunade formed hand seals at nearly shadow-like speed for half a minute.

Finally, Tsunade tapped Hyuga Ao's forehead. The purest strand of Yin Seal chakra within her body traveled from Hyuga Ao's brow to the rest of her body, completely activating the Yin Seal.

Tsunade pressed one finger against Hyuga Ao's forehead. As chakra poured in, the array patterns covering Hyuga Ao's body rapidly shrank and all disappeared into the center of her brows.

Tsunade withdrew her finger, revealing a small diamond-shaped mark on Hyuga Ao's forehead.

"It's done," Tsunade confirmed.

"Phew." Hyuga Ao let out a long breath. It was finally over.

Tsunade tossed a scroll to Hyuga Ao. "This explains how to use the Yin Seal. Go back and read it slowly. It's not that difficult."

Hyuga Ao put her clothes back on, respectfully thanked Tsunade, and turned to leave.

After walking out of the tent, Hyuga Ao felt that her legs were weak and limp. She was still in the recovery period after her fever.

She squeezed her palms and stamped her feet. "Strange. Why does it feel like my whole body's senses have become much sharper?"

Setting aside her doubts, Hyuga Ao, her entire body weak and tingling, slowly dragged herself back to her tent.

"Whenever a doctor says it'll be quick, it means nothing! They're just trying to distract you! You can't trust them!!!" Hyuga Ao concluded.

Shaking her head, Hyuga Ao returned to her tent and began reading the Yin Seal manual.

The Yin Seal was a Sealing Jutsu created under Mito's direction, with the help of the First Hokage and the Second Hokage.

The original idea came from Mito seeing Senju Hashirama's inhuman constitution. She was afraid that by the time she grew old, Hashirama still wouldn't have aged.

This ninjutsu had been conceived from that fear. Yin referred to women, and it also referred to time. The Yin Seal locked away a woman's years.

She had searched through Konoha's secret collection and, with the help of the brothers Hashirama and Tobirama, broadened the concept, eventually creating the Yin Seal as it existed now.

The Yin Seal combined Sealing Jutsu, Medical Ninjutsu, knowledge of the human body, certain principles of bloodline limits, and some of the essence of chakra.

There should originally have been a Yang Seal as well, but the Senju brothers had died too early, so only the Yin Seal remained.

After reading the introduction, Hyuga Ao followed the instructions and sent the chakra she had left that day into the Yin Seal. She could no longer resist the drowsiness surging over her like a tide and soon fell into a deep sleep.