[Mount Myōboku · Beneath the waterfall]
Icy water cascaded from a hundred meters above, pounding against Naruto. Bare-chested, he sat cross-legged on a rock beneath the waterfall, letting the torrent scour his body. This was no ordinary waterfall-it was the "Sage's Spring," one of Mount Myōboku's Three Great Sage Lands. Its waters held abundant natural energy that could temper the body and increase its affinity for natural energy.
"Hang in there, kid!" Sage Fukasaku shouted from the bank. "The waters of the Sage's Spring will keep battering your meridians, forcing the chakra inside you to merge with natural energy. It'll be painful, but if you endure it, your Sage Mode can reach perfection!"
Naruto clenched his teeth, veins bulging on his forehead. The water brought more than a physical battering; it tormented his mind as well. Each impact felt like countless needles piercing his skin and traveling through his meridians to every part of his body. Worse still, the natural energy was forcibly merging with the yang power within him. The two forces repelled and attracted each other, stirring up violent surges in his chakra pathways.
"Aaargh!" Naruto could not hold back a howl of pain.
"Keep quiet!" Sage Shima barked from the bank. "Keep your mind steady! Let the natural energy flow on its own. Don't resist it, and don't force it!"
Naruto drew a deep breath, forced down the pain, and adjusted his breathing as the two sages had instructed. Gradually, he found the pain inside him easing, replaced by a warm sensation-as though he were soaking in a hot spring, warm currents flowing through his meridians into every limb and bone.
A faint golden sheen began to spread across his skin.
"It worked!" Fukasaku exclaimed in delight. "His yang power and natural energy are starting to merge!"