That was...very succinct and well studied. I really don't have much to say about the the chakra creation discrepancy argument that Jake and I were using now. Fukasaku's wording in the original text seems to be referring to chakra circulating throughout the body rather than the individual components in the moulding process.
Thanks a lot. Indeed, at first maybe it was my rather poor explanation that didn't made sense, that's why I decided to revisit the whole training arc and check with the original transcripts. Now, moving on.
It all goes back to my initial thoughts that I presented around the forum, sometime ago. So, my point here was that following the rules of Frog Sage Mode, Sakura would possibly handle it. However, might I add that the rules for each Sage Mode are different. It's a thing that I recently discovered, so to speak, while re-reading the manga. It was something going through my mind for quite some time, but re-reading the manga, those previous ideas, BluestarSaber's observation and Morgaine4's observations as well + studying again some manga situations, I have come to the conclusion that each Sage Mode is different.
I will try to explain in other post though, for the moment, let's address what you said here.
I would like to present a noticeable piece of information regarding the chakra circulatory system and the Byakugou though.

The Yin/Byakugou seal is characterized as being the pinnacle of chakra control - i.e. the ability to regulate and utilise chakra in an efficient manner via concentration in the body as well as exerting it in a properly configured form (or jutsu as it's known).
Now we know that the chakra siphoned towards the creation of the seal is not externally released. From what can be deduced, creating the seal, which entails having precise regulation and stability of one's chakra, involves concentrating that energy towards a single node or chakra point out of the 361 that exist inside the human body. Supposedly the node in question is the one on the forehead which I took the liberty of indicating in the above panel.
Yes, that is what it seems to be the Byakugo seal. Besides the evidence presented by you, simply put, Byakugo seal is a fuuinjutsu, acting like a storage device. You simply store your chakra into it. In order to store the chakra, you must go through the process of focusing part of your chakra in that exact point for 3 years in order to get it.
Chakra is apparently created in the internal organs which are connected to the Inner Coils System.

Actually, chakra is created by the cells in each organs as it's show by Sakura's explanation.

Cells that have attached to them chakra tubes like explain by Tsunade back in 346 when they were discussing RasenShuriken's risks.

In the diagrams used in the panels to describe the developmental process of senjutsu, we can see that sage chakra is anatomically centred in the chest area of the body. The same area where conventional chakra is forged in the internal organs.
From what it seems in the Frog Sage mode, yes, sage chakra would be anatomically centered in the chest area, however, we have had Naruto's case, in which his chakra would be centered in his belly area.

So I guess it depends?
Given the conditions of the situated chakra in Sakura's forehead, what she would need to do in order to develop sage chakra is distribute it from the seal to these aforementioned organs in her body. Meaning that she would have to release the seal or draw power from it without releasing it like what Tsunade did in the Invasion of Pain arc. But is this possible?
What Sakura would need to do, is just release the chakra in her body and then gather natural energy within her, if the case of SSM is similar to FSM. I will explain later why I think they're different.
And yes, it's possible. Once you release the chakra, it goes directly into your body. What Tsunade did in Pein arc is released her chakra from her seal and poured it all into Katsuyu, so basically, first, her chakra went through her body and then transmitted it to Katsuyu in order to heal the civilians. So yes, it's possible.
Unlike Sakura, the ones who were able to acquire senjutsu (besides those who were implanted with the Curse Seal) all possessed naturally large capacities for chakra production and transference or they managed to enhance their chakra creating capacity through DNA supplements. The chakra created in the internal organs and their presence throughout the body would be abundant.
Besides Naruto, Hashirama and Sasuke, we're not sure of their capacity of chakra production. With Juugo we just know he attracts Natural Energy, that's how his body is made, but we don't know how much chakra he has. If you're referring to Kabuto, he utilized the 3 of them in order to make his body stronger, not to have larger chakra. As presented, Snake Sage Mode requires a strong body, that's why Orochimaru wasn't able to become a Sage and Kabuto was. Because Kabuto utilized other's DNA to posses a stronger body, not a larger chakra reserve.
I will explain differences and so in another post I am planning to do, with infos and such so if you'd wait a bit, I'd be grateful. :)
Sakura's situation is a bit different though. Her natural capacity is fairly average. The main arguing point for developing senjutsu is that she can utilise the reserves from her seal and convert it into sage chakra. With the information given by yourself, Chatte, it's evidently possible to combine natural energy with already developed chakra. But from that same information it's depicted that sage chakra, just like regular chakra, is augmented in the same area where the chakra producing organs were shown to reside.
The way Sakura would be able to draw Sage chakra, if the SSM has the same requirements, she'd have to release the seal, have all that chakra in her body and then after drawing it, mold all together for Sage chakra.
Sage chakra isn't augmented, sage chakra is used to augment your own chakra. That's the point of it. Instead of utilizing your own chakra, the chakra that the body produces and uses, therefore, you can get tired, you use the sage chakra, therefore by using it, the one who utilizes it has the means to last longer in a battle.
It's even explained in the training by Fukasaku.

My question here is can the chakra from that single node on her forehead be channeled to these organs for conversion?
Yes, it is possible. As shown in the previous picture with Naruto when he concentrates his chakra from the belly he then channels it into his whole body.
Plus, think about it, Sakura's own battle type depends on channeling her chakra. Meaning, she channels her chakra from a part of the body and releases it into her fist for example. So if this works, so does viceversa.
To make an analogy, think about water. You have it in a bucket and then when you throw it out it spreads to a surface. Same principle here.
Hope you got the analogy as I kinda suck at explaining, lol.
I also would like to emphasise the inessentiality of Sage Mode for Sakura. Her primary role is acting as the medical operative of her squad. Direct confrontation with the enemy is a secondary profession which she only partakes in if necessary and it's generally only defencive.
With all due respect, I think you're wrong in this particular thinking. Yes, her primary role is acting as a medic operative for her squad, however, the fact that she's not just a regular medic ninja, just like her master, already breaks this pattern. By this thinking, Tsunade shouldn't have learned all those ninja techniques because her primary role is a medic. However, she did, which allows her to act as a combat ninja.
Also, we mustn't forget it's the same resolve she passed down on Sakura.

Take a look at Kabuto. He was a primary a medical ninja as well, but that didn't stop him from learning Sage Mode. Why should it be a reason for Sakura? Plus, we don't know yet what Slug Sage Mode does in order to decide if it's inessential or not.
Senjutsu is a school primarily focused on shinobi who act as the main offensive force in battles. How would such a practice benefit someone who scarcely engages in combat? If the intention was to augment her medical ninjutsu then it would be impractical to use because a sage has to maintain a stationary position for several moments. Those moments could mean the difference between life and death for any shinobi who might be critically wounded and would be in desperate need of a medical shinobi. You can see the conflicting imperfections of the mode relative to her medical duties.
Once again, with all due respect, I think you're wrong. Sage techniques are described as techniques that help you last longer in battle, not necessarily focus on shinobi who act as the main offensive force. If that would've been the case, don't you think we would have a mention? Just because the Frog Sage Mode happened to be mastered by Jiraiya/Naruto who were more the offensive types, that doesn't mean that it's a rule generally available for everyone.
As explained by Fukasaku, Sage Techniques are techniques that makes one last longer when in battle, who augment all your initial taijutsu, ninjutsu or genjutsu.
And with the fact that Sakura is not just a medical nin, she's also a combat one, that leaves enough interpretation or whatever you want to name it, that she would acquire sage mode. It doesn't matter how much she's involved or not in battle, what it matters is that if she's getting involved, she can utilize SM in order to switch roles.
And as I said, we don't know exactly what SSM does in order to just trash the idea along the way.
Also, yes, the one who acquires SM is shown to have to maintain a stationary position in the beginning, however, we're shown that the rate is different. Naruto was having problem in the beginning and needed to stand still for long, but with time, he did master to gather it quickly, whereas Kabuto was shown that he acquired it quite quick, he just waved the sign, we saw the snakes growing and voila, he was in SM. And all this time while he moved from his initial position. But the gathering, he did it through the snakes.
Who is to tell that Sakura can't gather it having Katsuyu attached to her shoulder like Tsunade does or through her seal which is in a stationary position? As I said, we don't know exactly the requirements of SSM in order to make those presumptions.
Moreover Sakura's current abilities can already handle the vast majority of injuries efficiently. Anything that she can't personally handle is manageable through Katsuyu or Naruto's chakra which is remotely linked to her network now.
Still, that doesn't excuse why she shouldn't or couldn't learn SSM/use it. Who knows what Kishi will pull up in the next chapters, thus SSM would be required?
What you're describing is a similar thing that people told me when I first theoretized that she'll get the seal. Why does she need it, bla bla, she wouldn't need it for anything.
And I described a single scenario: The alliance gets hurt massively, thus they'd need recovery and she would be doing it via the seal, similar to Pein arc with Tsunade.
Thing that happened.
It's Kishi's story, he can pull whatever situation he wants in which SSM would be necessary or of help.
The other arguing point for senjutsu is directly linked to the Sannin parallel. Unlike Jiraiya and Orochimaru, Tsunade has not been stated or shown to have dabbled in the senjutsu arts. She might have taken some fundamental basics and applied them to her jutsu, but it's never been shown to use natural energy. This argument of parallelistic fulfillment only exists if the person whom you're being compared to has consistently shared the same attributes. Tsunade doesn't use senjutsu to our knowledge. And in spite of recent events, neither does Sasuke (for the moment) as he was using the abilities of Juugo. It wasn't derived from his own power. With Perfect Susanoo's inevitable appearance we know that Sasuke will be capable of matching Naruto's bijuu mode. If he is going to match Naruto's senjutsu, then he may very well request of Orochimaru to give him another Curse Seal or he could make use of Juugo's DNA which is implanted into his chest cavity and gather natural energy that way.
Even if Sasuke developed senjutsu, it doesn't correlate to Sakura eventually developing it. Naruto and Sasuke are intentionally grouped together because they are supposed to represent the dualistic natures of light and dark, Senju and Uchiha. Their senjutsu is directly linked not only to their own personal conflict with each other, but to their parallel of Hashirama and Madara (since it is the means through which they will likely surpass them).
Sakura, on the other hand, has no relevance to that conflict. She's merely a circumstantial bystander who has observed events as they unfolded around her ever since P1. Hashirama and Madara have no established connections to her as the only link which is remotely familiar to them is the one with the former's granddaughter for reasons that exist independently of their ideological war. In that sense, she's no different than Kakashi who has never used senjutsu and will likely play no role in the final fight outside of spectating for it perhaps.
So in conclusion to this argument, there is reason to believe (besides the technical process which you disputed) that Sakura never has and never will use senjutsu.
Yes, it does come from parallelism. At least one of the students of the Sannins, for now Jiraiya's and Orochimaru's are utilizing Sage Mode/natural energy.
We have Jiraiya - Naruto
Orochimaru - Kabuto, Sasuke
The third one would be Tsunade, that true, she wasn't shown but you're forgetting that things can still happen plus we have the saying with "the new generation surpassing the old one".
Who is to say that Sakura will not surpass Tsunade by doing something she didn't master? Thus, surpassing her teacher as well. Jiraiya mastered it but not fully, Naruto surpassed him in the sense of fully mastering it. Orochimaru found the source and all, but couldn't master it due to his body, only acquiring a lower mode, as stated by his disciple, an imperfect Snake which we could link it to Orochimaru's ability to transform himself in the 8 headed white snake, same as Hakuja, who was a big white Snake.
Thus Kabuto did it later. Indeed, he used some different methods but he did it himself.
Now, we have Tsuande's case which didn't utilize any form but she does have knowledge of Shikkotsu forest and all that. Who is to say she couldn't master it or didn't have time or whatever the case? This point could be further explained when the revelation would be done.
As I said, if Kishi wants to build a scenario that requires that, he will, nothing is stopping him.
Regarding Sasuke, indeed, he utilizes Juugo for getting Natural Energy, but in the end, if you look at it, 2 out of 3 students of the sannins have the ability to utilize in a way, natural energy.
Kishi is very picky about these things and he has a thing with the triad concept in the Narutoverse, why should he break this one now?
And indeed, they are parallel of Madara and Hashirama, but he overall context was Madara and Hashirama fighting for the sake of the village, the main factor being Kurama. That's when we have Mito being introduced in helping Hashirama with Kurama. So in a way, even if she isn't directly linked to the main battle, she could be helping Naruto with Sasuke.
It's the same thing as with the Sannin parallel, Jiraiya + Tsunade against Orochimaru. Mito + Hashirama against Madara [so to speak].
Then we have Naruto + Sakura against Sasuke. And the cover of 616 pretty much made it clear.
So, once again, excuse me if I think you are wrong with this presumption. I stand by what I say. Of course, if you'd nitpick with details, things wouldn't make a lot of sense. Like in a way, Sakura getting the Byakugo seal, for some, it didn't make either, though I kept offering them reasons to why she'll get it, though foreshadowing was less when compared to her male counterparts.
With that being said, I plan on coming with a new post explaining some differences between each SM and the possibility of SSM and SSM for Sakura. And why Hashirama's SM is not SSM and it's more related to the Shinjuu tree.
Edited by Chatte, 14 October 2013 - 11:50 AM.