Natsume took a gentle breath, immediately feeling comfortable all over.
To him, natural energy was like the spiritual energy in cultivator novels—a power that existed within the world itself.
While chakra was a foreign system.
But because the threshold for the former was so high, it was never widespread.
Natsume guessed that Sage Mode was each of the three great sanctuaries' attempt to mix natural energy with chakra, successfully lowering the difficulty.
Otherwise, why wasn't the native system based on pure natural energy?
"Let's go."
Tsunade led the way confidently.
Natsume looked around, everything was new and fascinating.
"Tsunade-sama."
A slug, half as tall as a person, greeted them with a gentle voice that didn't match its appearance.
Natsume had always wanted to say—the voice was really nice.
He remembered in the anime, it was voiced by Mamiko Noto.
"This is Natsume-sama, isn't it?"
The slug twisted its feelers and asked.
"Just call me Natsume."
Natsume hurriedly bowed. "It's an honor to meet you, Slug Sage."
The whole of Shikkotsu Forest looked like it had countless slugs, but there was only one consciousness.
That was the thousand-year-old Slug Sage.
The Great Toad Sage and White Snake Sage were both powerful and famous; the Slug Sage, equally so, stood at the pinnacle of the ninja world.
But compared to the other two, the Slug Sage had a milder personality.
"Don't mind it. I call every contract holder 'sama'," the slug said, tone rising a little. "It's been a long time since a human has come to Shikkotsu Forest. I'm glad to see you both."
Natsume could understand.
If he lived alone in one place for a thousand years, he'd go crazy.
And there was no internet.
The Great Toad and White Snake Sages had pupils and disciples, but the Slug Sage had none.
"Natsume wants to try training in Sage Mode," Tsunade explained their purpose.
"Go see my true body," said the slug, pointing the way and turning to leave.
Tsunade and Natsume continued deeper into the forest.
Along the way, they saw many slugs, big and small.
Clearly, despite being a single consciousness, the Slug Sage had split itself into countless clones—out of boredom, it seemed.
Left hand fights right hand.
After passing through the pale forest, Natsume finally saw the Slug Sage's true body.
It was… huge.
So huge it was endless.
Natsume's entire vision was filled with white.
The Slug Sage's massive head lifted slightly, looking at the two of them—tiny as grains of sand—and spoke in a gentle, feminine voice: "Long time no see, Tsunade-sama. And the new contract holder, Natsume-sama, you're quite interesting."
"Interesting" referred to him using the slug for a reverse summoning date.
Of all the contract holders in its long life, only Natsume had done such a thing.
But it thought it was amusing—something to pass the time.
Natsume blinked.
He hadn't reacted yet.
Why did it say he was interesting?
Could the Slug Sage read minds?
No, that couldn't be it.
Otherwise, it wouldn't have called him interesting, but something else entirely.
"To train in Sage Mode, the first requirement is a large amount of chakra. You barely qualify," the Slug Sage sized him up. "Second, and harder, is the talent to sense and absorb natural energy. Many ninja are blocked by this and can never access Sage Mode."
"How do I know if I have the talent?" Natsume asked at the right moment.
"Take off your clothes," the Slug Sage replied.
"…?"
Natsume paused. Apparently, Naruto trained this way too.
Fine, it's not even human—no big deal.
Wait, Tsunade's here too.
Natsume instinctively looked at her.
Tsunade's lips curled into a smirk.
You were so bold last night—why shy now?
Natsume gave her a look.
Tsunade pretended not to understand. "What, is there something you want to say?"
You wicked woman—so greedy for my body.
"I need to take off my clothes," Natsume said directly.
"Sensing natural energy is dangerous. With me watching, I can help if anything goes wrong," Tsunade offered, giving a reasonable explanation.
"Tsunade-sama, since that's the case, you help him apply it," the Slug Sage decided before Natsume could answer.
A big wooden bucket appeared out of nowhere.
It was filled with a clear liquid.
Mount Myoboku used toad oil to enhance sensing.
This must be Shikkotsu Forest's unique product.
What was it?
Natsume thought it was best not to ask.
Tsunade was instantly embarrassed, frozen on the spot.
She'd only meant to tease Natsume, never expected to actually see him.
Now she had to help apply it all over—wasn't that worse?
Natsume took off his clothes and sat cross-legged.
If he hesitated now, he'd hardly be a man.
Tsunade's heart pounded with a nervousness she'd never felt before.
She swallowed and reached out, gently applying the liquid to his back.
It was cold.
Natsume shivered slightly.
But Tsunade's hands were soft and warm.
"Close your eyes. Listen with your ears, feel with your heart," the Slug Sage instructed.
Natsume complied at once.
As the mysterious liquid was applied to his back, he felt natural energy slowly seeping in.
"You can do the front yourself," Tsunade hesitated, then said.
Natsume raised an eyebrow.
You were so bold just now—why back down now?
"Don't move," the Slug Sage added helpfully. "Once you're sensing, you can't move. Tsunade-sama, you'd better help him."
"…"
A slight blush crept onto Tsunade's face.
After a moment, she scooped up more liquid and slowly applied it to his body.
Natsume couldn't concentrate at all.
Any old man would fail such a test!
"Keep your mind empty," the Slug Sage said, noticing his expression. "Become one with nature. Sense the movement of natural energy by being perfectly still."
Too hard!
Natsume tried his best not to notice Tsunade's hands.
Thankfully, the ordeal ended quickly.
Half a minute later, Tsunade backed away, her heart finally settling a little.
But she couldn't calm down.
Why was it like this?
She'd bathed her younger brother before, but never felt anything like this.
Was it a mindset issue?
Tsunade looked at Natsume, sitting in meditation, lost in thought.
"Not bad," the Slug Sage said, clearly pleased. "At last, another contract holder who can train in Sage Mode."
The three great summoning lands were rivals, especially over their contract holders.
Recently, Mount Myoboku's had the upper hand.
Hearing this, Tsunade couldn't help but smile.
Sage Mode's power boost didn't need explanation.
Look at Jiraiya—Sage Mode took him from an ordinary Jonin to one of the very best.
Natsume already had Wood Style. With Sage Mode too, the revival of the Senju clan was in sight.