Konan intently looked at the massive ball of mostly blue in the distance, "So... that is our home?" She tilted her head with a difficult expression.

Instantly, all four remaining women turned to look at it, showing either astonishment, frowns, or disbelief.

Rei already informed them about the universe, space, and things like that but accepting it was another thing. For people of Elemental Nations, the world beyond their continents simply may not even exist since almost nobody tried to get there and those who did, didn't return.

Hell, residents of some more remote countries still believed the world was flat! It was really mind-boggling how differently developed certain places in the Elemental Nations were.

Alas, now... here it was. Their home planet was right in front of their eyes.

Right there, they could see the Elemental Nations. They had the same shape they sported on many maps. It was unmistakable. The surprise though came from the fact the Elemental Nations were but a small fraction of land visible on the planet.

"The reason why nobody ever returned to the Elemental Nations after leaving to explore is clearly visible from here." Rei started, pointing to the distance, "Our home is too isolated. The closest land to the Elemental Nations is to the south and even then it is... hmm, by my crude estimation, at least, six thousand kilometers away."

"And that is a problem, why? I could run that far on water." Mei pipped in, cutely tilting her head in genuine confusion.

Rei smiled at her. She always overestimated others because she had a bad habit of comparing them to herself. It was something she picked up after being trained by Rei and Konan while having only them to measure her improvement.

"It's because you are not average, you dolt." Ringo snorted and rolled her eyes as she crossed her arms under her chest in a provoking manner.

Before Mei could return the verbal fire, Rei interrupted the argument before it could even start, "Yes. Water Walking is not too exhausting but even then, an average Jonin can travel up to a hundred kilometers on the water before he runs out of chakra, entering a chakra exhaustion state, which, on the open sea would mean he would drown." He explained, "Even those Elite Jonins and S-rank ninjas with the biggest chakra reserves back at home do not have chakra reserves to get further than five hundred kilometers on water."

"Unfortunately," Ringo decided to continue as she had some knowledge about these matters since she was the Kage of Kirigakure. "Even the ships the Land of Water has right now," And everybody knew these were the best ships in the entirety of Elemental Nations, "can't cover six thousand kilometers on an open sea. That's plain suicide. You gotta count the storage capacity for supplies, the durability of the ship in case it is caught in storms and many more variables that... yeah." Ringo shrugged, "Not happening. The ship would most likely fall into pieces halfway through the journey because of storms."

"And then there is that..." Rei added with a wry smile, "The dark blue patches strewn all around the Elemental Nations in the radius of two thousand kilometers."

"What do you mean?" This time it was Pakura who asked. "Doesn't that just mean the ocean is extremely deep in those places? Why should that be a problem?"

Rei looked around and noticed that none of his girls actually had an inkling why that would be a threat. He sighed and rubbed the bridge of his nose. 'I should probably have expected this. They all grew up in Elemental Nations, after all. How could I expect they would think outside of the box?' He helplessly lamented.

For one last time, Rei glanced at Tsunade, making her owlishly blink. Shaking his head, he decided in which way he would explain it.

"Tsunade," Rei started, "what are the two energy sources accessible to humans?"

At first, Tsunade scrunched her eyebrows, not understanding what that had to do with it but nevertheless, she dutifully answered, "Chakra and the nature energy."

"And what else can use nature energy, I dare say, even better than humans?" Rei asked again.

This time, Tsunade's eyes slightly widened. She quickly understood what Rei meant and the reason why he asked her was that she did research on this. "Animals. Most of them have a way to innately accept nature energy into their bodies, becoming what we call chakra beasts."

"You want to say in these dark blue spots where the ocean is the deepest is a habitat of strong chakra beasts?" Konan asked in a way that suggested she found it hilarious.

"Ah, don't think about it like that." Rei rebuked, "Chakra beasts get stronger as they age. The more nature energy they absorb, the stronger, smarter, and better they become. Naturally..." Rei glanced at Tsunade.

"Naturally," She continued for Rei as she understood this had to do with the results of her research, "they also possess chakra. Nature energy would kill them if their chakra was not balancing it in their bodies. They do this instinctively and as such, they take in nature energy, improving their bodies, which, in turn, in time improves their chakra reserves, which then allows them to take in more nature energy, making them even stronger in one unending circle." She summed up.

"You want to tell us the chakra beasts are instinctively using Senjutsu?" Ringo raised an eyebrow at Tsunade.

"No. In fact, Senjutsu was based on that ability of theirs. You gotta understand, the chakra beasts are doing this extremely slowly. Senjutsu is like… drawing nature energy to the limit of your body on purpose for a quick boost that is not permanent. In the short term, it provides far more power. Because you are trying to stuff the most nature energy your chakra reserves can contain, however, it is dangerous." Tsunade replied. "Senjutsu being derived from that also means that while I use Senjutsu, my body is slowly but permanently absorbing nature energy, and is getting stronger, which increases my chakra pool… yeah, that's why I actually started researching the chakra beasts in the first place."

"Summons are chakra beasts, aren't they?" Pakura suddenly realized.

"Yeah," Rei grinned, "Summons are just chakra beasts who live in an environment that is extremely favorable for them, quickening the rate of their 'growth'. For example, Mt. Myoboku is said to be the best place to learn Senjutsu because of the abundant nature energy there." He shrugged, "Hence the gigantic toads. And by the way, I think Mt. Myoboku is actually located in the middle of the Divine Mountains of the Land of Lightning."

"So... what? Is that why we must sacrifice chakra to summon them?" Mei mused, causing the people around them to stare at her in astonishment at the huge logical leap.

"... Yeah?" Rei unsurely nodded, "I mean... I have never studied the summoning scrolls but maybe the chakra the summoner sacrifices is indeed increasing the summon's chakra reserves, hastening its evolution. I mean... they sure as hell do not let people use them for free, right? A bit of chakra to get a massive animal fighting for you is also a bit too far-fetched."

"Anyway," Konan decided to return the conversation on its track. "Let's get back to the topic. Deep in the ocean? Chakra beasts?"

"Well, you see. The source of nature energy is the planet. Even this moon," Rei tapped his foot, "is a source of nature energy. It is small and weak but it is there, deep under the surface. Our planet is producing many times more nature energy. Plus the ocean is vast. There is enough space for multiple extremely strong and old chakra beasts that had centuries to grow without any natural predators and were a lot closer to the source than, for example, the summons. Do the math yourself."

"I see," Tsunade frowned, "In the Elemental Nations, the chakra beasts were hunted down. Only in some special places like the Forest of Demons in the Country of Demons you can find relatively strong chakra beasts. Even these are quite weak and a jonin can easily dispatch them. What Rei is describing is a situation where these chakra beasts had nobody hunting them and as such, they were allowed to grow..." Tsunade looked at Rei in astonishment, "You are not trying to tell us they are as strong as bijuu, are you?"

Now that got all of their attention almost instantly.

Rei, however, just shrugged. "I have no idea. All I got are the legends from the southernmost islands of the Elemental Nations. After all, the legends of the Sea Dragons, Water Serpents, Island Eater... whatever, has to be based on something."

"What's stopping them from coming to the Elemental Nations, then?" Pakura asked with a frown. The Land of Wind was located on the south of the mainland. If these chakra beasts decided to visit...

"The same thing that is preventing the bijuu from leaving the Elemental Nations." Rei said and paused, causing the women to lean closer to him, "No matter how intelligent, deep down, they are still animals. They have their territories. Why do you think the three-tailed turtle stayed close to the Land of Water for so many years? Why did Shukaku stay in the desert despite loving destruction? It's their turf and they simply loathe leaving it."

"Our world is a lot more complicated than we first thought, huh?" Tsunade chuckled.

She didn't expect an answer though.

"You have no idea."

So when a voice resounded from behind the group, they instantly tensed.