Kekkei Genkai

At this point, Kakashi Hatake felt no sympathy or kinship toward Zabuza Momochi. Going through the motions, he pulled out a scroll and sealed away Zabuza's Severed Arm, intending to hand it over to the Medical Squad once they returned to the village.

Once he had finished all that, Kakashi toppled straight forward and went splat on the ground.

"Ah, Kakashi-sensei collapsed again," Sakura Haruno said.

"Mm-hmm, just as expected," Naruto Uzumaki said, nodding nonstop.

"..." Kakashi wanted to complain too. Did they think it had been easy facing the Demon Zabuza's storm of slashes? The man wielded that door-sized blade so tightly it was impossible to penetrate. He could make countless mistakes without consequence if he missed.

But one mistake from Kakashi, and his head would have gone flying.

He could only force the Sharingan's dynamic vision to its limits and desperately make out the path of every slash... Of course he had collapsed after pushing the Sharingan that hard.

And he had used a Chidori as well, squeezing his Chakra dry. Right now, every inch of Kakashi's body hurt.

"..." Sasuke Uchiha was equally speechless. If you said their Jonin was unreliable, he was actually quite reliable. But if you said he was reliable, he was also, in some ways, rather unreliable.

Wu Yu pointed at the half of the broken sword the Demon had left behind on the ground. "Should we take that back? It looks like a powerful ninja tool."

"That thing's useless now." Kakashi was helped back to his feet by Tazuna.

Seeing that the ninja had said their piece, Tazuna finally stepped in to smooth things over. "Hahaha, I'm truly sorry you had to face such a powerful enemy! In any case, let's head to my home and get some proper rest."

On the way, Kakashi Hatake, carried on the old man's back, explained things to the Genin. "What Zabuza used was the Kubikiribōchō, one of the Seven Swordsmen of the Mist's seven renowned blades! That sword can absorb blood to regenerate itself..."

"Isn't that amazing? I'll go get it back—" Naruto Uzumaki cried, only to be grabbed by the collars and dragged back by Sasuke Uchiha and Sakura Haruno.

"The Kubikiribōchō's regeneration formula was most likely sealed within its hilt," Kakashi said. "The broken piece is nothing more than a chunk of fine steel now..."

The rest of the journey was peaceful, and the group of six arrived at Tazuna's home.

It was a cluster of wooden houses built over the sea. A Four-Leaf Windmill stood outside, slowly turning amid the drifting mist.

Accompanied by the sound of waves, Wu Yu and the others crossed the wooden walkway and pushed open Tazuna's front door.

Tazuna's daughter, Tsunami, was a twenty-nine-year-old widow. She had been waiting alone at home, and when she saw her elderly father return safely, she finally relaxed. She thanked the Konoha ninja profusely, then hurriedly brought out bedding and helped Kakashi lie down to rest.

"I'll probably... be bedridden for two or three days."

Lying beneath the covers of his floor bedding, Kakashi Hatake spoke with a hint of embarrassment under the gazes of the three members of Team Seven.

With the thick skin to openly study Icha Icha Paradise in public, he normally would not have embarrassed so easily. But the Survival Exercise was still far too fresh in his memory...

Sakura Haruno asked curiously, "Didn't Kakashi-sensei take us on a mission the very next day last time?"

"Last time..." Kakashi mused. "A very capable medical ninja treated me, so I recovered much faster."

Very capable indeed. There had even been a lap pillow!

Wu Yu sat cross-legged against the wall, looking around the little wooden house. It was truly bare as a bone... The Wave Country was so poor it was practically about to pawn its pants. The rumors had not been exaggerated... His gaze met Tsunami's as she entered carrying hot tea. Before he could speak, she smiled and said, "It's fine. We really are poor, so please bear with us. There isn't any good tea to serve you."

"Not at all." Wu Yu poured himself a cup of hot tea. He had no idea whether it was brewed from seaweed or something else, but the taste was strange... He could not help taking another sip.

Naruto Uzumaki, who had been holding it in for ages, finally could not resist. Gesturing with his hands, he asked, "Kakashi-sensei, was that weird ice wall a ninjutsu too? Is there really a Release of that attribute?"

As Sakura Haruno and Sasuke Uchiha accepted their tea, they quietly pricked up their ears as well.

Lying down, Kakashi said, "That was Ice Release, a type of Kekkei Genkai... A Kekkei Genkai is a new nature created by using two Nature Transformations at the same time. Ice Release is Wind plus Water."

"Mm-hmm!" Naruto nodded as he listened, then tilted his head in confusion. "That sounds easy!"

"Easy?" Kakashi said. "Sasuke, try creating Lightning Release and Fire Release Chakra at the same time."

"..." At Kakashi's words, Sasuke smoothly created Fire Release Chakra in his left hand. Then he spread his right hand, intending to create Lightning Release Chakra—but not only did he fail, even the Fire Release Chakra in his left hand dissipated.

Kakashi said, "Performing two Nature Transformations simultaneously is like asking someone to write poetry with their left hand while solving physics problems with their right. It's nearly impossible. The talent behind Kekkei Genkai is, in plain terms, the innate ability to use two different Nature Transformations at once. The key is not even the 'two,' but the 'at once.'"

Naruto Uzumaki was utterly lost. It was so mentally taxing that smoke practically seemed ready to pour from his ears.

Sakura Haruno's curiosity had been piqued. Looking from Kakashi beneath the covers to Sasuke beside her, she asked in confusion, "Then what about Sasuke's and Kakashi-sensei's Sharingan? Those unusual eyes seem to be a Kekkei Genkai too. Which two Nature Transformations created them?"

Kakashi Hatake said, "That..."

"Eliminate all impossibilities, and whatever remains, however improbable, must be the answer."

Wu Yu counted out five fingers in turn and smiled. "Sasuke can't perform Lightning and Fire Nature Transformations at the same time, and he doesn't possess Water, Earth, or Wind affinities. That only leaves..."

"Yin and Yang?" Sasuke Uchiha and Sakura Haruno said in unison.

"A combination of Yin Release and Yang Release? I see!" Sakura Haruno had not yet learned Yang Release and did not understand the difficulty contained in her own words. She only felt immensely relieved to have resolved a question that had been weighing on her mind.

"..." Sasuke Uchiha lightly pressed a hand over his eye. Yin plus Yang created a new nature—the Sharingan's ocular power?

He thought of the woman named Kaguya by Wu Yu's side.

Sasuke clearly remembered that Kaguya had used the Yin-Yang Release Technique Wu Yu spoke of to create those two rabbits for Wu Yu and Tsunade.

Was the Sharingan a Kekkei Genkai of Yin-Yang Release? That Yin-Yang Release capable of creating life from nothing?

Was that why these eyes possessed such unimaginable potential...?

Once again, Sasuke recalled those Mangekyō Sharingan shaped like triangular shuriken.

With Kakashi staring fixedly at him, Wu Yu felt a little uncomfortable. He touched the blood and hair samples stored in his pocket, then rose to his feet. "I'll go take a look around, in case Gato sends more ninja to launch a surprise attack."