Tree Climbing and Water Walking Are the Strongest Secret Arts in the Ninja World

Hatake Sakumo walked to the edge of the training ground, where several sturdy pine trees stood. Their bark was rough, covered in a thin layer of moss. The morning dew had yet to dry, glistening damply in the sunlight.

"Tree climbing."

Minato froze for a moment. "Tree climbing?"

His tone carried the confusion of, I'm already six years old. Why do I need to learn tree climbing?

"Not with your hands." Sakumo planted one foot against the trunk.

Then he walked up.

On the vertical trunk, he moved as if walking on level ground. Every step was steady, neither hurried nor slow. When he reached a point about three meters above the ground, he stopped, turned to face the three of them, his hands still tucked into his pockets.

"Use chakra to adhere to the soles of your feet and anchor your body to the trunk. The principle is simple. Too little chakra won't hold you up; too much will shatter the bark. You need to find the balance."

He jumped down from the tree, landing without a sound.

"Begin."

Fugaku went first.

He took a deep breath, gathered chakra at the soles of his feet, and stepped onto the trunk. The first step held. So did the second. On the third, his foot suddenly slipped, and his body tipped backward. He flipped in midair and landed cleanly. He had not fallen, but his expression was far from pleasant.

Fugaku said nothing. He took another deep breath and stepped onto the trunk again.

This time, he got farther, slipping only on the sixth step.

Then the seventh.

Then the tenth.

Bai Ye watched from the side and noticed that Fugaku improved at an astonishing rate. After every failure, he adjusted his chakra output, and the next attempt was more precise than the last. That kind of learning ability truly deserved the word "genius." His body was like a finely calibrated instrument, automatically correcting its parameters after every failure until it found the exact value.

Minato was second.

When he stepped onto the trunk, he wore the expression of someone trying something especially fun. The first step held. The second held. Then the third, fourth, fifth...

He reached the branches in one go.

The whole process took less than ten seconds.

Fugaku stopped practicing and looked up at Minato, who was crouched on a branch and waving at them with a smile that said, This tree is so easy to climb. Fugaku's expression did not change, but his right foot ground against the dirt.

"How did you do it?" Fugaku asked. His tone was calm, but Bai Ye caught a trace of unwillingness in it.

Minato thought for a moment, tilting his head as he crouched on the branch. "It's just... a feeling? You have to keep the chakra steady. Not too much, not too little. It's like carrying a bowl of water. If you use too much force, you'll spill it. If you don't use enough, you'll drop the bowl."

Fugaku said nothing and turned back to continue practicing.

Bai Ye walked to another tree.

He did not climb immediately. First, he pressed a hand to the trunk, feeling the roughness of the bark, the dampness of the moss, and the grain running through the wood. Then he closed his eyes and gathered chakra at the soles of his feet.

On the first step, the instant his foot touched the trunk, his chakra output was too strong. The bark gave a soft crack, splitting with a thin fissure.

Bai Ye drew his foot back and adjusted.

On the second step, his chakra was too weak. The moment his foot touched the bark, it began to slide down.

On the third step, he found the feeling. It was not "outputting chakra," but "using just enough chakra." Not forcing it, but getting it exactly right.

The feeling was subtle, like pinching a butterfly between two fingers. Too much force would kill it; too little would let it fly away. Chakra formed an extremely thin adhesive layer between his feet and the trunk. The thickness of that layer determined whether he stood on the tree or fell from it.

Bai Ye stepped onto the trunk, his body parallel to the ground, and did not fall.

He began to walk upward.

One step, two steps, three steps, four...

At the seventh step, his chakra supply fluctuated slightly, and his foot slipped. He stopped at once, adjusted, and continued upward.

"You made it up too!" Minato sounded as happy as if he had climbed up all over again himself.

Bai Ye steadied himself on the branch and looked down at the stretch of trunk he had just climbed. Seven or eight marks of varying depths were left in the bark, all from when he had adjusted his chakra. Each mark corresponded to a calibration, like the steps of solving a problem written onto the tree.

"Your chakra control," Fugaku said from below, his voice low, "is better than I thought."

Bai Ye looked down at him. "Thanks."

Fugaku froze. He probably had not expected Bai Ye to say "thanks." In his impression, Bai Ye had always spoken very little—so little that sometimes Fugaku forgot the boy could speak at all.

"Continue." Fugaku stepped onto the trunk again.

Once the three of them could run up and down the trunks, and Minato could even dart back and forth between several trees like a monkey, Hatake Sakumo called them to a shallow stream beside the training ground.

"The principle of water walking is the same as tree climbing." Hatake Sakumo stood on the water's surface. The stream only covered the soles of his shoes, and he stood firmly atop it as though he were standing on a sheet of transparent glass. "The difference is that a tree trunk is fixed, while the water's surface is constantly moving. You can't output chakra just once. You need to sustain it while continuously adjusting according to the movement of the water."

He walked forward a few steps. Small ripples spread across the surface, but his feet never sank.

"The key is rhythm," Sakumo said. "Water has a rhythm to its flow, and your chakra output needs rhythm too. Not too fast, not too slow. It has to stay in sync with the water."

Minato was the first into the water.

The instant he stepped onto the surface, his body swayed. He output too much chakra, sending water splashing everywhere, but he immediately adjusted. On the second try, he stood firm. Then he started walking. One step, two steps, three steps. At the fifth step, a gust stirred the water, and his chakra output lagged half a beat. His right foot sank to the ankle.

But Minato did not sink.

The moment his right foot touched the water, he increased his chakra output and lifted it back above the surface. The entire process took less than a second.

"That was close." Minato smiled and turned to head back to shore.

Then Bai Ye stepped onto the water.

First step, he sank.

Not slowly. The instant his foot touched the surface, he went straight down to the knees. Icy stream water flooded into his shoes. Bai Ye climbed out, took off his shoes, poured out the water, put them back on, and tried again.

This time, he stood steady for one second before sinking.

The third time, he lasted three seconds. Then he sank.

The fourth time...

"Your chakra output is too rigid." Sakumo's voice came from the shore.

Bai Ye turned to look at him.

"You're treating the water like solid ground. The ground doesn't move, so you only need to output a fixed amount of chakra. But the water is always moving, so your chakra output has to move with it." Sakumo walked over the water and crouched down, placing a hand on its surface. "Feel it."

Bai Ye placed his hand on the water.

The stream flowed through his fingers, cold and carrying a constant push. Its direction, speed, and pressure changed every second. Some places had faster currents, some slower ones, and some held small whirlpools.

"Your chakra output needs to be like water," Sakumo said. "It can't be a stone that sinks the moment you throw it in, and it can't be a ball of fire that explodes and scatters. It has to be like water—blending into the water."

Bai Ye closed his eyes and gathered chakra at the soles of his feet.

This time, he did not think about how much chakra to output. He only thought about making his chakra like water.

He stepped forward.

He did not sink.

A layer of chakra formed between his feet and the water's surface. It was not rigid, but flexible. It moved with the waves, like an invisible layer of water blending into the stream.

Bai Ye opened his eyes and took a step forward.

He stood firm.

Another step.

Firm again.

By the time he reached the middle of the stream, Minato was clapping beside him. Fugaku did not clap, but the corner of his mouth twitched upward again. Seeing him smile twice in one day, Bai Ye felt that today might be some kind of special occasion.

At some point, someone else had appeared beside the training ground.

A middle-aged man with spiky white hair, dressed in a green vest and holding an unlit pipe in his mouth, leaned against a pine tree as he watched the three children climb. He had arrived without a sound, as though the wind had blown him there.

Hatake Sakumo did not turn around, but his shoulders shifted slightly.

"Third Hokage."

Bai Ye and the other two stopped at the same time.

The Third Hokage?

"Just passing by." The newcomer stepped out from the tree shadows, sunlight falling across his face—Hiruzen Sarutobi, the Third Hokage. A faint smile rested on his face as his gaze passed over the three children, lingering for an extra moment on Minato and then on Bai Ye.

"Sakumo, are these the three you mentioned?"

"Mm."

The Third Hokage took the pipe from his mouth and tapped it against the tree trunk. "Keep practicing. Don't mind me."

The three children looked at each other.

The Hokage had told them not to mind him, but the Hokage was standing right there watching. That alone made it difficult not to mind him. It was like someone standing behind you during an exam, watching your paper, then saying, "Keep writing. Don't mind me." In theory, you could ignore them. In practice, every word became much more careful.

Fugaku was the first to resume training. His movements were noticeably more meticulous than before, every step as precise as if measured with a ruler.

Minato, on the other hand, did not change much. He had already been in that state. He even jumped into the water, dashed straight to the opposite bank, and moved faster than before, as if performing for the Third Hokage.

The Third Hokage's eyebrow twitched.

When it was Bai Ye's turn, he took a deep breath and focused once more on the chakra beneath his feet. Whether the Hokage was watching or not did not change that feeling.

The Third Hokage did not stay long. After watching for a while longer, he put the pipe back in his mouth and turned to leave. After taking a few steps, he suddenly stopped.

"Sakumo."

"Mm?"

"The Land of Wind's delegation will arrive next month."

Hatake Sakumo said nothing.

"You only need to know about the border matter."

"All right, children, practice well. Every great warrior throughout history started with these two things. Hehe, by that logic, tree climbing and water walking are the strongest secret arts in the ninja world." With that, the Third Hokage vanished into the small woods.