Naruto: I am Uchiha Shirou

After the intense seggs, Shirou lay nestled in Tsunade's embrace like a baby, completely letting go and falling into a deep sleep. From time to time, his lips would twitch slightly.

"Evil Uchiha, even asleep, you're so restless."

In a strange posture, Shirou sat on the hospital bed, eyes half-closed, deeply asleep. Tsunade was sitting on his lap, tilted at an awkward eighty-degree angle.

Yet, she still lovingly held him against her chest. When she felt the suction against her chest, her face flushed red, but she put on a fierce expression to mask it.

However, her eyes had already softened, gazing tenderly at his handsome, sleeping face. For the first time, Tsunade allowed herself to shamelessly caress and examine such a face so gently.

"He's quite handsome, not embarrassing to be seen with. His fair skin is as good as mine. If we had children in the future, their skin wouldn't be bad either...

These eyebrows are nice too. When he's asleep, he looks like a little puppy. But awake, he's such a handful…"

Tsunade murmured to herself, saying who-knows-what. Her personality was such that once she made a decision, she never regretted it.

"But doing it with him feels like dealing with a monster. No wonder neither Mikoto nor Kushina ever complained. Even with my Senju bloodline, I could barely handle it. If it weren't for the fact that he hasn't fully recovered…"

Hours passed. No one knew how long Shirou had been asleep, but he finally opened his eyes slowly. His dazed vision was filled with a bright white scene and a hint of pink.

Then, realizing what was in his mouth, Shirou's face flushed red, and he quickly let go.

A thread of saliva stretched between them—truly worthy of the Uchiha clan's reputation for precision in tightrope pulling.

"You're awake?"

"Sister Tsunade?"

Shirou gave an awkward smile. Last night, it seemed, had gotten a little out of hand, maybe even reckless.

Suddenly!

Tsunade let out a cold snort. She was trying to cover up her embarrassment from the emptiness she felt as Shirou moved.

Tsunade glared at him fiercely but said nothing.

Her personality was such that once she made a choice, she wouldn't regret it.

With composure, she began using medical ninjutsu. Shirou awkwardly tried to change the subject, speaking in a small voice:

"Sister Tsunade, maybe Kushina can help you recover later?"

"Hmph! We'll deal with that later. For now, there's something else you need to do!"

Hearing this, Shirou froze. Looking at Tsunade, who was completely unashamed before him, he felt puzzled.

Tsunade's medical ninjutsu was, as expected, the best in the ninja world. Although their intense seggs last night left her feeling a bit out of practice and torn, she healed herself in just a few moments.

"Let's get to business."

Tsunade snorted coldly, her long legs making a graceful turn as she got off the bed. Her high heels clicked sharply against the floor.

Shadow Clone Jutsu.

In an instant, Tsunade created two shadow clones. As they moved to clean up the evidence left behind from the night, Tsunade's real body walked to the cabinet.

She pulled out a light blue outfit, put it on, and returned. The area around the bed was already spotless.

Even the deformed steel frame of the bed bent out of shape from last night, was restored to its original condition under her immense strength.

"Let's discuss the important matter."

With a calm expression, Tsunade walked to the bedside and suddenly pulled open her clothing. Shirou's eyes widened in shock.

"Sister Tsunade, this is the 'business' you mentioned? Is this serious?"

Caught off guard by her boldness, Shirou was momentarily stunned. Tsunade, however, let out an annoyed laugh.

"You are an evil Uchiha. What are you thinking? I said it's business, so it's business!"

"I didn't finish explaining last night's report. Your cursed seal Sage Body is different from our Senju clan's ancestral abilities. Specifically, when you apply the cursed seal to someone else, it carries a portion of your genetic energy into the recipient's body…"

Seeing Shirou's confused expression, Tsunade sighed and began explaining in detail.

"To put it simply: when you apply the cursed seal to someone like Mikoto, it carries a portion of your internal energy. That energy doesn't just include the Sage Body's power but also your other internal energies, such as genetic energy.

Currently, your body contains Wood Release energy. That energy didn't come from someone else; it was absorbed. Or rather, it repaired and awakened broken, dormant genes already in your body. That's why you haven't activated Wood Release yet—but your body has grown stronger…"

At this point, Tsunade sighed deeply and shook her head.

"Through the balance of the Sharingan and Woode Release's energies, I've found that the two are heading in completely different directions. It might be related to the unknown fate shared by the Uchiha and Senju clans over millennia.

To simplify, imagine a ninja born with all elemental affinities. This ninja has two children, but each child only inherits one of their parent's affinities. The rest of the affinities aren't lost entirely, but rather hidden or dormant. Over generations, those dormant genes fragment and weaken, eventually lying dormant forever."

Listening to Tsunade's explanation, Shirou was astonished. He couldn't help but think, Man, this is Tsunade for you. She's amazing! With just some data, she managed to deduce all this intel.

But then again, it wasn't surprising. In the original story, Orochimaru had already started suspecting such things later on. Otherwise, how could Kabuto have guessed that the evolution of the Mangekyo Sharingan led to the Rinnegan?

It's worth noting that Tsunade was no weaker than Orochimaru. Unfortunately, in the original story, her hemophobia caused her to waste over twenty years.

Now, however, Tsunade had chosen a different path. She had become obsessed with power early on and had spent the past two years thoroughly studying Tobirama's research notes.

In the current ninja world, there likely wasn't anyone more knowledgeable than her in this field.

"Hey, hey! Are you even paying attention?"

Tsunade's annoyed voice snapped Shirou out of his thoughts. After all, it was quite cold in the lab, and she had unashamedly exposed herself to make a point.

In the next moment, her face flushed red as she realized Shirou was staring straight at her exposed breast. Though embarrassed, she couldn't help but feel a sense of pride. Hmph! These assets of mine will ensure our children never go hungry.

"You still don't fully understand your own body. For example, if you applied the cursed seal to me right now, the genetic energy you've absorbed might fill in the gaps in my dormant genes, possibly activating or repairing them."

"Of course, this is just a possibility. I also suggest you reapply the cursed seal to Mikoto every three months. Since your body now contains fused Wood Release cells, it's constantly becoming stronger…"

Tsunade's calm explanation was interrupted by Shirou's increasingly odd expression. She realized what he was thinking and couldn't help but laugh.

"Don't get any weird ideas. This method only works if the recipient already has dormant genes. It can't create something from nothing. In other words, the cursed seal's erosion of the body is a two-way process. While it erodes, it also integrates."

After hearing her explanation, Shirou finally understood.

"So that's how it works. I get it now. If the recipient has dormant genes, it can activate or repair them, but it can't create something entirely new. The ability is more like filling in a missing 0.5 to make it a 1."

"That's one way to think about it, but it's not entirely accurate. Your unique body theoretically allows for the fusion of other Kekkei Genkai, but the process would take a long time."

Realizing this, Shirou was alarmed. It wasn't the cursed seal technique itself that was so powerful—it was his unique body that made it possible.

"However, the cursed seal is extremely dangerous. My body has only been able to adapt to its energy after two years of constant research and experimentation, including injecting myself with it during the Land of Rain battles."

The cursed seal's survival rate was notoriously low, but Tsunade had tested it on herself and confirmed her body's compatibility. It was the result of years of careful study.

"Sister Tsunade, why does this Cursed Seal have to be placed there?!"

Although Shirou understood the reason, he still looked awkwardly at Tsunade. To leave such an ugly Cursed Seal mark on this flawless, dazzling, and irresistible masterpiece? It felt like ruining a perfect work of art at its peak!

Seeing Shirou's reluctant expression, Tsunade glared at him in irritation.

"Hey, hey! Did I tell you to put it there? I said the center! What are you thinking?! If your Cursed Seal is on your neck or any other visible spot, it'll look bad and draw attention."

"Right now, all the major ninja villages already have intelligence on you. They know about the Cursed Seal's abilities. A ninja must keep their trump cards hidden."

Tsunade's explanation made it clear she wanted to conceal this ability. Understanding this, Shirou nodded in realization.

"Sister Tsunade, bear with it for a moment, I'll be gentle…"

Gently parting the flawless, radiant mountains, Shirou opened his mouth. His canine teeth slowly extended and softly pierced Tsunade's delicate skin.

In an instant, a surge of scorching energy flowed in, causing Tsunade to let out a muffled groan. Soon after, a black, three-tomoe mark appeared on her chest.

As the Cursed Seal process concluded, Shirou tenderly licked the wound.

"Sister Tsunade, this is now my exclusive mark. From now on, you're mine…"

Before he could finish speaking, Tsunade coldly put her clothes back on and smirked:

"Dream on. I did think about having two kids—one with the Uchiha name and one with the Senju name—but now? Hmph!"

She made it clear: it's already generous enough that she didn't insist he become Senju Shirou, and he still dared to dream?

This left Shirou wide-eyed in disbelief. No way! The three most beautiful blossoms of Konoha seemed like they were all turning rebellious.

"Stop wasting time! Get dressed quickly—Mikoto and Kushina will be here soon. Remember, Mikoto's Cursed Seal needs to be refreshed every three months. As for Kushina, I'll arrange a compatibility test for her. If it works, this power will be a great asset."

...

Although Shirou had regained his mobility, he still lay on the hospital bed, surrounded by various monitoring devices.

"Your body has partially fused with Wood Release's cells, but the concentration this time is too high—more than before. They've already invaded your abdominal area. Now that you're preparing to use your forbidden technique, Chimera Jutsu, I'll monitor the devouring process."

At the bedside, Tsunade, dressed in a loose blue robe, couldn't hide her curiosity as she stared intensely at Shirou.

Mikoto and Kushina entered the room.

Mikoto entered with a serious demeanor, ready to take notes, while Kushina couldn't help but sneak glances at Shirou's exposed body, swallowing nervously.

It felt like Shirou had grown even more.

Completely bare, Shirou took a deep breath and said firmly:

"I'm ready to start!"

Forbidden Technique: Chimera Jutsu!

As Shirou activated the forbidden technique, a diamond-shaped mark appeared on his palm. He pressed it against his abdomen, and the white traces on his skin visibly started to fade. At the same time, the surrounding monitors began to beep incessantly.

"Mikoto, take notes! Kushina, stay alert and be ready to seal or heal at any moment."

"Understood!" Mikoto and Kushina nodded seriously, dividing their duties.

Tsunade's sharp eyes darted back and forth between the changing readings on the monitors and the transformations in Shirou's body. As the forbidden technique absorbed the cells, the excitement in her eyes grew more intense.

"As I thought! My hypothesis was correct. Although you have this devouring factor in your body, it requires an external force. By using this forbidden technique, it's as if the factor is being directly enveloped and activated..."

Tsunade excitedly explained using professional terminology. Although Mikoto didn't understand a word, her Sharingan's incredible ability allowed her to record everything verbatim.

"In simpler terms, as long as you don't overuse or deplete this power, it will slowly be absorbed and fused into your body completely. This forbidden technique is practically tailor-made for you."

Tsunade praised the results enthusiastically, even bursting into laughter.

"No wonder they say a ninja develops jutsu based on their abilities. Even the most brilliant successors can only refine techniques to suit themselves. Otherwise, they'll never surpass their predecessors."

Tsunade continued her analysis, carefully observing the data. She confirmed that the unstable Hashirama cells in Shirou's abdomen had been completely devoured, nodding to herself in satisfaction.

"All metrics are normal…"

"Still, we can't be careless. Although the cells have been devoured, there's still a risk—especially in the early stages of absorption. We'll need two months to observe initial signs of fusion before we can be certain."

Tsunade calmly analyzed the situation. Meanwhile, Shirou wiped the sweat from his forehead, exhausted.

He was truly drained. The reckless invasion of Hashirama cells in his abdomen, combined with various seals to suppress their rampage, had left him unable to control his chakra. After a night of stabilization, Tsunade had loosened the seal just enough for him to gather the chakra required for the forbidden technique. Only then had he been able to breathe a sigh of relief.

...

While Tsunade was busy in her laboratory, the Third Hokage's face darkened in his office.

"Danzo! Look at the mess you've caused. The research on Wood Release has leaked. If this raises suspicions among the other villages, can you bear the responsibility?!"

In the Hokage's office, Shimura Danzo's expression was equally grim. However, he faced his mistake without evasion, nodding and saying in a deep voice:

"Hiruzen, I will take full responsibility for my oversight."

Seeing Danzo bow his head, the Third Hokage's anger subsided slightly. Letting out a heavy sigh of disappointment, he muttered:

"Though the intel has leaked, at least the Foundation acted promptly. The Wood Release cells haven't fallen into enemy hands."

Hearing this, Danzo nodded and replied solemnly:

"The laboratory was destroyed in the battle, and the remaining experimental materials were completely incinerated. No spies escaped."

Reassured by Danzo's guarantee, Hiruzen's expression softened slightly, though worry still lingered.

The ninja world feared three things: Tailed Beasts, the Mangekyo Sharingan, and Wood Release. His real concern was that this incident would reignite the fear of Wood Release in the other villages, prompting them to secretly conspire against Konoha.