AN: Note that I do not own Naruto, Naruto Shippuden, or any of the characters from either Anime. This work is a fanfiction written out of my love for the series and not in any attempt to make a profit.

Proofread by: Author and Kyluxia

A few hours late with this chapter, but what can you do? Not the easiest thing to write, this was. Had to change the first portion of the chapter after taking a break, realizing I was writing myself into a corner with a few contradicting decisions. Hopefully, I don't make such mistakes in the future without noticing them.

Chapter 51: Needle rush and engaging topics

Apparently, Kotone's chakra control was even more impressive than the twins had first thought. She was capable of not only controlling her needles with chakra but skilled enough to do so from a distance. The only reason she had remained by their side, was due to their conversation, as well as the extra attention their unique biology required.

Halfway through the Acupuncture treatment, the twins finally figured out exactly what it was Kotone was doing. Any tenketsu the needles had struck, seemed numb, so they hadn't realized it at first, thinking the numbness to be a result of their pinned nerves and Koneko's medical chakra. However, following their internal chakra flow, they could tell that there was a lot more going on. The physical and mental balance within their chakra was off, even if barely noticeable, it was.

Attempting to trace the irregularity back, revealed it to be a result of Koneko's treatment, caused by the connection of nerve signals, blood, and medical chakra to their chakra network. Kotone's medical chakra ensured that there would be no permanent or even temporary damage to their nerves or blood vessels, but keeping her chakra going for a prolonged period of time, no matter how little chakra she used, she would eventually run out, and for a civilian with small reserves, that time would be incredibly short. Fortunately, Kotone's technique solved the issue, using the twins' own body to support the treatment, using a fraction of their own physical and mental energies to mold additional medical chakra. The chakra that while theirs, was guided and used by Kotone.

The twins hadn't even realized their body worked in such a manner, but apparently, their blood carried an enormous amount of potential physical energy, and in their nerves, an enormous amount of potential mental energy. The numb feeling wasn't from their neves being pierced, since they couldn't actually feel the needles anymore, but from the energies being released. The imbalance they had detected in their Senjutsu chakra, was a result of excessive physical and mental energy flowing into their chakra network, following the path the needles created between the four, otherwise exclusive, networks. Knowing just what was going on, the twins carefully adjusted the process, taking control of any excessive leakage, and redirected it into their regular reserves.

As Sakura shared their observations with Sai and Kotone, both of them listened, and Kotone admitted that she hadn't realized how aware Shinobi were of their own chakra, or that she had been messing up their control. Sakura assured her that it wasn't an issue and that she was an exception to the norm, so she shouldn't worry. It wouldn't be a problem unless it ended up happening in the middle of battle.

Following that train of thought, Heikō came up with some nasty possibilities to add to their fighting style. Managing to unbalance an enemy's chakra network on a larger scale could end up being an incredible card to have up their sleeve.

The treatment itself, while mildly pleasant and relaxing, didn't seem to have too many medical advantages over the traditional Shinobi way of using the Mystic Palm Technique. However, it was no less effective, and unlike the Mystical Palm Technique, it could actually access the inside of the chakra network of the patient without passing through any other tissues first. It was a far more effective use of chakra, limited only by the patient's own physical and mental energy reserves, as well as the user's chakra control. Sadly, it really was far too time-consuming to ever become a Shinobi standard.

The Acupuncture session came to a close with an unexpected change as the last needle was placed in their back. Naturally, since far from all of their tenketsu were located in their back, and plenty of them weren't even reachable with the needles, there were still a lot of needles left when Koneko announced that she was done placing needles, and would now begin the last step of the treatment.

Before Sakura could ask her what the last step was, they felt it. Almost as if their blood had been replaced with liquid fire, and their nervous system with brittle ice, they felt both in perfect clarity within their bodies. The pressure of their chakra system shot through the roof as it sped up to unnatural speeds, and just as quickly as it had begun, it was over. It hadn't hurt, but it had been a shock unlike any other and had left them fully aware of the placement of the smallest capillary within their body. Their mind was alert, their body feeling fresh, fully rested and their chakra seemingly flowing freer than previously. Astounded, the twins simply took the feeling in, stunned and awed. It wasn't until they tried to move that they noticed that all the needles were already removed from their back.

"What was that?" Sakura asked, looking to Kotone for an answer, receiving a smile.

"We call it an awakening. It is slow working, but with each needle, we put the body in a sort of trance. The gradual process is unnoticeable, as it is a natural ability of the body. Then, when I removed my chakra, as well as all of the needles at once, you snap back into alertness. The sudden change forces your body to experience a form of hyper-alertness, it also has the benefit of cleansing both the circulatory system and your chakra network in one fell swoop." Kotone explained while Sai and the twins inspected their own bodies and chakra networks in their own way. They found that what Kotone had told them seemed to be true, as their chakra seemed to flow easier, and they could still feel their nerves and blood stand out in their body, bending, moving, and changing as they moved their body. It was a fascinating, as well as slightly disconcerting feeling, but using the Mystic Palm Technique, they confirmed that there was a change to their body. There were indeed traces of harmless, yet excessive substances that were rapidly disintegrating both within their blood and chakra. In addition, the twins could feel their chakra now acting differently within their chakra coils, almost as if expanding and contracting them at odd intervals. It wasn't anything significant, but it reminded them of the way some Shinobi would use water techniques to clean tiles during D-rank missions. It was almost as if their chakra had taken note, and was now scrubbing their entire chakra network clean.

"You do this for civilians as well?" Sakura asked, wondering if that was really wise, in someone who never actively used their chakra coils. Kotone nodded in confirmation.

"We do. It stimulates their chakra network and sometimes awakens it from the normally passive state. Regular civilians usually experience it as an awakening, making them feel more lively and energized. In some instances, they even manage to gain enough control over their chakra from it that they learn to actively mold more, and possibly even use it. Those that do, we make sure to check up on from time to time and teach the basics so that they at least don't hurt themselves.

Sakura nodded in understanding. It wasn't uncommon for Academy children of civilians to begin experimenting with chakra after first being taught how to mold it. The Academy did try to teach them discipline first, but there was always one or two foolhardy students that ended up hurting themselves, or simply exhausting their chakra to the point of chakra exhaustion as a result.

"I can see the benefits of regular treatments like this." Sai decided, getting off of the massage table, covering himself with his towel, just like the twins were. "I didn't even realize my body wasn't as physically fit as I thought it was. It seems there is still room for improvement within my training schedule." Sai concluded, making the twins wonder just what kind of training Sai did. While Sai obviously had muscles, they weren't as clearly defined as they would have expected. Even Naruto had more visible abs than Sai did, yet Sai seemed surprised that this training schedule could be improved. It was a good topic for them to pursue for the rest of the date. One that so far, didn't actually have any bad points after they had realized that the Acupuncture wasn't a painful waste of time. The only possible exception being the far too many opportunities for them to see each other with nearly nothing on. It felt a bit too intimate in Sakura's opinion, while Heikō simply considered it a good opportunity for two dating partners to show off their bodies. Sai wasn't bad-looking after all, and they had seen enough not to need to imagine him naked.

Just like with the sand bath, Sai and the twins got to enjoy separate baths, although they were located next to each other, making it just as intimate as they were meant to take a full-on dip in the mineral baths, meaning no towels. Fortunately for Sakura, Sai seemed to put very little stock in seeing them naked, which made it a lot easier to accept and ignore. Focusing on slipping into the cold water was also distracting enough that neither of the twins had the time to look at Sai as he did the same, discarding his towel in the process, just like they did.

Fortunately, for Shinobi, dealing with cold water wasn't as much of an issue as it would be for civilians. Chakra, in general, was an all-purpose body improving energy, even passively, it helped retain body heat, even if it couldn't prevent the loss entirely. Although, if one thought about it, it was a good thing, as any person retaining absolutely all of their body heat would rapidly overheat. Humans were meant to lose their body heat as a way to cool down, although, the twins had been considering developing a technique that would change that, by temporarily changing the functions of cells that resulted in so much energy being wasted as excess heat. After all, it was still energy, and if it could be preserved, changed into another form, it might be used elsewhere, rather than be wasted as it normally was. The idea, however, was still a work in progress and far from complete. Thus far, the only thing they had decided on was that it would require adjustable seals, something they had yet to learn about from Jiraiya.

"So, what does your training usually consist of?" Sakura decided to ask, taking their mind off of the chilling water, as well as the tangent of what to do with their heat loss.

"My training?" Sai asked, before deciding that it wouldn't hurt to discuss it with them. "Mainly, my training consists-" Sai began explaining, drawing the three of them into a discussion where they shared their training exercises and habits, explaining why they used certain exercises, and how they had changed over time as their skills improved. The topic proved not only to be interesting, allowing them to learn more about each other but also learn a thing or two from each other's training exercises. The twins, able to provide a medic's perspective on certain things, while Sai could offer a ROOT operative's perspective in kind.

By the time it was time to leave the cold mineral bath, they had already forgotten about the cold, and had yet to finish their discussion, pausing it in order to change to the hot bath.

However, this time, unlike the sand bath and cold mineral bath, the hot bath wasn't a small one that they took separately. Something the twins realized as they stepped out from the changing room, and saw that the hot mineral bath was one, single, big hot spring. For just a moment, Sakura was dismayed that they wouldn't be able to continue their discussion with Sai until after the bath, only to realize that there was no divider present and that the exit from the men's changing room exited to the same bath.

"It's a unisex hot-spring!" Heikō concluded cheerfully.

AN: So, the last part of the date is about to be here. Not a typical first date, is it? Sharing a hot, naked bath with someone.

Now, for the insinuation that a chakra network can be cleaned, suggesting it can get dirty, clog up, and such comes from my interpretation of chakra being considered something like a gas, or liquid when within the body. It flows through channels known as chakra coils that make up the chakra network. It can be changed to take on different properties, and clearly has some form of physical presence, yet not necessarily mass. The way I see it, chakra is mostly energy, but part of that energy forms physical particles. This is why the Rasengan, for example, can physically grind against objects and be seen, because it collects a high amount of particles.

Now, the question is, what purpose do these particles have, and what properties do they have when separated? Well, this will be touched upon later in the story, but the quick version of it that most of these particles are elemental particles that are introduced into the chakra network through the physical energy that is used to create chakra. These particles form from an excess of physical energy that the chakra interacts with within the heart, granting a Shinobi their elemental affinity.