Naruto: The Birth Of Fenrir and his Keeper

"I can't believe you encouraged my dad to up my training regimen! What happened to us being best buds?" wailed a distraught Renji as he and Keitaro lay on the ground gasping for breath under the large tree in the training field after a truly grueling training session.

"That's what you get for showing off in front of your dad, don't blame it on me." Refuted Keitaro, though he made sure not to look Renji in the eyes as he did.

"You two truly are quite a handful, still as dramatic as always." Kazuki's unimpressed voice sounded from above them and they both looked up to see him lying on one of the larger tree branches. 

"Regardless of your current sorry state, good work to both of you. You gave a pretty good showing today and I'm pleased to see that you're taking this training seriously. It's too early for you two to be taking a break though. The physical training is over, but you still have chakra training to get too."

Both of the boys let out groans at the mention of more training, but Kazuki didn't seem deterred.

"Oh come on now, chakra training doesn't require much physical activity, both of you are literally going to be sitting there on the ground anyway, might as well make the best of it."

He tossed out two bowls that landed in front of both Renji and Keitaro, who both sat up with a resigned sigh. There was no escaping anyway, so they might as well get it over with.

Both of them poured the water from their water bottles into the bowls until they were filled to the brim, and each picked a small green leaf from the tree under which they had been resting. With their preparations complete, both of them placed the leaf in the bowls, allowing the leaves to float on the surface of the water slowly swishing from side to side under the influence of the evening breeze.

Keitaro looked over at Renji who had already sat in a meditative position, his legs crossed while his hands were placed on either side of the bowl in front of him. 

While at first nothing seemed to be happening, the leaf that had been floating on the top of the bowl of water slowly stopped moving around haphazardly, and actually started to swirl in a circle around the brim of the bowl. The most interesting part about what was happening was that the water in the bowl itself wasn't actually moving all that much, only the leaf was slowly swirling around the bowl.

This was a chakra control exercise that Kazuki had introduced to both boys back when they had first started training. At that time he had tested Keitaro on the leaf concentration method and was pleasantly surprised when Keitaro was not only able to keep the leaf attached to his forehead, but able to do so for over two hours.

After that, he had introduced Keitaro to the leaf in the bowl method that he had personally developed for training in chakra manipulation and chakra efficiency.

Keitaro had already known about the importance of chakra control, but chakra efficiency was a new concept to him that had been quite an eye opener. 

Chakra efficiency was simply the amount of actual value you were able to get out of the chakra that you utilized. There were many people who had comparable amounts of chakra, yet if they used the exact same class of jutsu, there would always be one person who would run out of chakra first, even if they used the exact same jutsu at the exact same rate. 

In cases like this, for the most part the differences between the shinobis rate of chakra usage vs the amount of techniques used was a direct result of their chakra control and chakra efficiency. 

While increasing one's chakra control made it so that you could utilize complex jutsu with less chakra, chakra efficiency not only encompassed how much chakra you actually used, but how much extra chakra you pumped into a jutsu in order for it to work.

If the chakra pool could be considered a reservoir of water, then chakra control was the equivalent to a hose attachment that allowed you control the way in which the water stored in the reservoir was released. It could be released in the form of spray, a mist, a thin pressurized stream, or maybe even a simple trickle. 

Different jutsu required different streams of water in different forms, so the greater your chakra control, the more versatile the ways you could release the water from your reservoir. Yet there was another important thing to note, and that was the type of hose you utilized to release the water in the first place. That in this analogy would be related to your chakra efficiency.

If you simply needed to water your garden, while some plants would need to be misted, some flooded with water, and even more would simply need to be drip fed. Regardless of the way in which you would need to water your plants, you would most likely utilize the most logical thing, a simple garden hose, in order to water them. 

It would be quite impractical of you to use a fire hose, as it would be considered overkill, and while you would still be able to control the way in which the water came out of the fire hose, there would still be quite a lot of wasted water either way.

In the same way that even if you had great chakra control but poor chakra efficiency, you would still run out of chakra before someone who had both chakra control and chakra efficiency. You not only needed to be able to change hose attachments depending on the jutsu you wanted to use, you also needed to be able to change the hose itself to better accommodate the usage of the water in the reservoir.

So given that, how did the leaf in the bowl training affect and increase one's chakra efficiency?

The trick lay in its simplicity.

The aim was to move the leaf that was floating on the top of the water without causing the water itself to spill from the overfilled bowl. It was relatively easy for a shinobi to move around water while using their chakra, that was how they were capable of water walking after all, and it was because of this that the training was so effective.

You needed to use you chakra, run it through the water of the bowl, attack it to the leaf floating on the top of the water and then manipulate the movement of the leaf, similar to the way you would do in the leaf forehead exercise and move it around without allowing your chakra to affect the surrounding water while doing so. 

Use too much chakra and the water would be affected, causing it to flood out of the bowl, use too little chakra and the water wouldn't be affected, but neither would the leaf. 

The more adept you became with this technique, the more quickly you could move the leaf, and the difficulty could be increased by changing the way in which the leaf was moved. Instead of moving it in circles along the edge of the bowl, why not make it spell out your name? 

Why not do figure eights? 

Why even stop at just one leaf at all? 

Why not try to manipulate several leaves all at the same time, moving some at faster speeds than the others?

It was an ingenious technique that could very well improve anyone's chakra control and efficiency, but it was up to Kazuki as to whether he would publicize it or not. Something that would most likely not happen. 

If he hadn't even shared it with the wider members of the clan, why would he share it with the village at large? This was something that was passed down amongst a shinobi's direct lineage and Keitaro was able to get in on the action because he had impressed Kazuki.

How many other tips and tricks were hidden away in certain lineages throughout Konoha? How much farther would the power of the whole village be if these things were shared amongst the people of the village? 

Keitaro stopped his mind from wandering and focused on his own bowl of water. Thinking about those sorts of things wouldn't do him any good so it wasn't worth wasting time over them. 

Instead he wondered whether he would finally be able to move his leaf without spilling the water from his bowl this time around.