That natural energy in Ryoâs body was activated by Chakra. What he didnât expect was that natural energy didnât have to be deliberately guided to be able to merge with Chakra.
Whenever the Chakra merged with that energy goes through a part of his body, that part will turn into ice, and the natural energy within that Chakra will be reabsorbed.
So after full ice elementization, all the natural energy within Ryoâs body will be integrated into his Ice body and it can be mobilized at anytime.
Ryo tried an Ice release Jutsu while in that elementization state. It was as Fukasaku described.
The natural energy within his body is 1st to fluctuate. Then a part of it enters the water that heâs about to freeze. What happens then is that the Natural energy in the air would be attracted by Ryoâs own natural energy. This pushes the external wind natural energy into the water, freezing it.
Whenever the natural energy within him is fully consumed (as freezing requires a lot of natural energy), Ryoâs body canât supplement it by external energy, so Chakra is used as a self-regulatory mechanism.
After some experiments, Ryo became certain that the key to his Ice Elementization was this internal natural energy. It was activated by Chakra, and is attracted to external natural energy. But it didnât have the other effects of its regular counterpart.
So he called Fukasaku, and told him about the progress he made. However, he concealed the part concerning this internal natural energy.
âRyo chan, you have already understood natural energy. Now you need to feel it around you. By feeling it flow into you using the oil, you must grasp that feeling and translate it into making it flow into you without the oil.â
Because he didnât have to worry that Ryo would be overwhelmed by natural energy, Fukasaku only came to help him when he needed guidance. He spent his times training Jiraya elsewhere.
In the Manga, the time that took Jiraya to master Sage mode wasnât really precised. Ryo also didnât know when he was there to study it.
Today, since they are both disciples in Mount Myoboku, so Jiraya was actually in a way, Ryoâs senpai!
Jirayaâs 1st step, meaning entering Sage mode with the help of the toad oil, was a success. Without using it, he could also sense and use natural energy. Itâs just that he wasnât able to balance it it properly with his own chakra.
Ryo, who understood well natural energy now, was actually pretty familiar with it. After all heâs been using it for ice mode for over 3 years. So it only took him a few days to sense the worldâs natural energy without the oil.
Through all these days of practice, and especially after discovering the natural energy within his own body, Ryo has been thinking about finding a way to combine the 3 energy sources he has to enter sage mode.
His only concern was his attempt will consume his natural energy. If heâs willing to use sage mode, heâll have to find a way to supplement it.
Ryo didnât want to experiment too much before solving this problem. He once again called Fukasaku who was really impressed with his progress on arrival.
For the next step in his training, Pa didnât give Ryo a precise method. But he suggested that he should sit down and get a feel for his ice mode.
Ryo tried to use what he learned about the attraction of external Natural Chakra to his own, by exposing his natural energy to the outside world. The wind and water parts of the external natural energy were drawn to his own like moths into a flame.
Using that gathered energy; he tried using Ice release, and what happened was that none of his Chakra was used except for what he needed for water release.
The problem of overusing Chakra in his ice mode was finally solved after all those years.
Ryo felt finally at ease. But then he discovered the flaw of this technique. Because of the mobilization of part of his internal Natural Ninjutsu, he couldnât actually complete elementization. There was always some palm sized part of his body that didnât turn into ice. Such a thing could be a fatale weakness for him in combat.
Ryo reabsorbed his own natural energy, and the external one that he gathered began to dissipate slowly.
âIf only I can gather it and store it!â Ryo was thinking out loud.
âKid, you can try using your [Yin Seal].â It was Jirayaâs voice appearing out of nowhere.
âJiraya-san, donât go around scaring people like that!â Ryo looked back at Jiraya.
âKid, youâve made great progress with your training. I just saw how you gathered so much natural energy. Boss just went home for dinner. So I came here to check out on you.â
Ryo was very grateful hearing this. Jiraya has known him for just a few days and now he cares this much about him. He showed his gratitude.
âDonât mention it little devil. Now, did you just say you want to store natural energy?â
Ryo nodded and said, âYeah, I have found a way to get a lot of natural energy fast, but no way to store it.â
âSo, you can try the Yin Seal that Kushina gave you, I was told by Minato that she taught you on how to use it.â
âJiraya san, it wasnât designed to store natural Chakra, and itâs not to be used frequently.â
âWell you can always try. If it turns out that you can store natural energy with it, I can help you change it making it more usable. Iâve seen its use and development after all!â
âReally Jiraya san?!â Ryo never expected such a pleasant surprise.
âOf course, a Sage always keeps his word! Now start trying to store natural energy!â He pointed at him telling him to start.
Ryo repeated the same thing he did before. This time, he gathered his natural energy in his Yin Seal.This caused a crazy inflow of external natural energy into it.
Ryo only took in the Wind and Water Natural energy, and was able to actually fill 1% of his sealâs storage. With his recovery rate, heâll be able to repeat this a 100 times, and totally fill up the seal in 1 weak!
He was feeling the natural energy being trapped in the seal and he knew it could seal natural energy.
So Jiraya went on and changed the release mode of the seal.
After being changed by Jiraya, the seal was still not comparable with that of Tsunade. It was releasable at will whenever it had Chakra in it, with the ability to turn it off too. But its weak point was that it was only refillable after being totally drained.