The Most Useful Jutsu

The morning sun marked the start of a new day. Arashi slowly stopped circulating nature energy through out his body. He couldn't feel any immediate increase in his strength but he knew his body was slowly being strengthened from the inside. He feel more energetic than the previous day.

He had an inkling if he continued circulating nature energy through out his body, he could achieve a more powerful version of sage body than Hashirama. Though it was a slow process, it was better than achieving it through using cells of Hashirama and implanting them to his body. He really didn't want to do that before he had any knowledge of human genetics.

His future goal was to create Otsutsuki bloodline by combining all the distributed bloodlines, but he didn't want to directly introduce to his body without any experiments. He didn't want to become disfigured like Kabuto. He would research them properly and find a new way of altering his gene without changing his body excessively.

He already had a plan to increase his medical knowledge. But for that he wanted to find 2nd Hokage Tobirama Senju's lab and research's about his seals and bloodline. For this he needed Tsunade's help to persuade her grandma to tell her the location of the hidden lab. If anybody knew of its location, it must be her.

Clearing his head of unnecessary thoughts, he completed his morning rituals and went to nearby training ground in the Senju compound to test his physical improvements.

In his village, he already trained with his father regarding different combat styles. Sometimes Kushina also joined him in his training. Though Uzumaki had more stamina than normal shinobi, without training even they would get rusty. He also learned some kenjutsu styles before but only basics. He preferred hand to hand combat than sword fighting. He wanted to be a close combat ninjutsu specialist.

As he reached the training ground he was surprised to see Kushina, Nawaki and Tsunade already doing their own training. Kushina and Nawaki were currently having a running competition. Both of them were already panting hard but nobody was backing down. Tsunade was practicing her punch and kicks. She had weights on her arm and legs. She was also panting but still maintained her consistency.

Watching them Arashi felt he was late. They must have been training before sunrise. He went ahead and greeted them.

"Good morning everyone. Sorry I am late."

"Good morning Arashi." "Good morning big brother Arashi." Everyone stopped what they were doing and greeted him. From yesterday Nawaki had started calling 'big brother'. He accepted it. He felt good to have a younger brother. Being the only son of Uzukage, he most of the time was left alone. So he liked Kushina's company every time she came to visit him.

"We didn't wake you up early because we thought you were sleeping." Tsunade said while wiping her sweats with a towel.

"Its ok. From tomorrow I will wake up early. I am also joining you guys in morning training. We can all train together."

Suddenly Arashi was reminded of an important jutsu for training. He looked at Tsunade while trying to decide whether to ask or not.

Looking at his distressed face Tsunade spoke "If you have anything in your mind, ask. I am not going to scold you or anything. You don't have to be afraid of me."

Listening to her words, he was reminded of her future self who most of the time lost her temper and punched anyone in her way. He was terrified of her monstrous strength. Timidly he asked "Can you teach me the Shadow Clone Jutsu?"

Listening to his request Tsunade was startled. Though it was a B ranked jutsu, it had a requirement of having large chakra reserves.. Only jonin and above could learn this jutsu.

'Arashi is an Uzumaki. He and Kushina will have no problem of chakra requirement. Maybe they can learn it. It will help them for sure.' Tsunade thought while deciding to tech them. But Tsunade had forgotten an important detail about the jutsu. The memory transfer of clones to real one which would cause a headache. Often shinobis were overwhelmed by the information and fainted.

"Ok I will teach it to you and Kushina." Hearing only Arashi and Kushina could learn Nawaki became upset. He felt her sister didn't care for him anymore. Looking at his face Tsunade could already deduce what he was thinking.

"Nawaki you can't learn it now. So don't make that face. If you have chakra as large as a jonin then I will teach."

"Now both of you remember the hand sign. I don't know if you know the use of this jutsu. but I will tell you the details. Actually this jutsu is pretty much a versatile jutsu. This jutsu allows the user to create one or more copies of themselves. The user's chakra is evenly divided between themselves and their clones: creating one clone will give it half the user's chakra, creating two clones will give each a third of the user's chakra, and so on. Depending on how much chakra the user has and how many clones they make, this rapid depletion of their reserves can be dangerous. Because of this, usually only those of at least jonin-level can safely use the standard Shadow Clone Technique. The Multiple Shadow Clone Technique – which creates hundreds of clones to the standard version's dozens – is unsafe to the point of being forbidden.

Unlike the basic Clone Technique, shadow clones are physically real. They possess the same clothing, damage, and transformations as the user at the time of their creation. Most tools and weaponry are copied when the shadow clones are created.

Because they are visually identical and possess the same chakra as the user, shadow clones are indistinguishable from their original, not even by dojutsu.

Once created, shadow clones can serve a number of purposes. They can be used as decoys, either by keeping opponents preoccupied or, because they can't be told apart, concealing the original's identity. If enough shadow clones are created, they can simply overwhelm an opponent, pinning them down or attacking from multiple directions. Shadow clones can also be used simply to assist the user, joining the user for tactics they can't do alone or being sent to carry out tasks while the user is busy. If, in the latter case, shadow clones encounter unforeseen obstacles, they will behave just as the user would in the same circumstances. Because they have their own chakra, shadow clones can perform other jutsu, including making more shadow clones.

Shadow clones usually disperse once they are struck hard enough, but they have been shown capable of enduring injuries for a time. When a clone's task is completed, it can disperse itself or be dispersed by its user. Once dispersed, the clone's experiences and remaining chakra are transferred back to the user. The shared experiences make shadow clones useful for intelligence gathering: a shadow clone can be sent into hostile territory, gather information without endangering the user, and disperse when finished, thus transferring what they've learned. Alternatively, shadow clones can recon an area, dispersing when they've found what they're looking for in order to let the user know the target's location."

After listening to Tsunade's description of the jutsu everyone was surprised the number of use of this jutsu. But the chakra requirement and the mental fatigue were it primary drawbacks.

Arashi decided to gave another important detail that he got from his future memories. This jutsu could be use to accelerate training.

"One more important usage I am going to add to the list. Shadow clones can also accelerate training periods. For example, by training alongside one shadow clone for one hour, the user will have two hours' worth of training experience once the shadow clone disperses. By using hundreds of clones, training that would usually take weeks or months can be completed within a few hours."

Tsunade and the others were left dumbstruck for sometime after listening to what just Arashi had revealed to them. If someone was to really train using such method for say 5 years, he could easily became a kage level powerhouse. They started trying to figure out how to use this jutsu and dreamed about achieving such power.

"But few people can use this method in this way. Because of how much chakra it takes to create just one shadow clone, and because the training itself will likely be arduous even without shadow clones, only shinobi with huge chakra reserve and high endurance can train in this way."

This broke all their day dreams of abusing the technique.

"Though we can still use this training. We can start with one clone and increase the number according to our capacity. This still can reduce our training time. Also if we can find different ways to reduce the backlash. Like canceling a clone one at a time rather than all together at a regular interval. Or we can simply increase our chakra reserve and endurance by using our main body while clones can use for chakra control exercises or chakra nature transformation exercises. We can also use them to read books or for research purpose while training our body. And lastly using them to cast ninjutsu will help us in many different ways."

Immediately after his explanation, Tsunade and Kushina performed the hand seals and their clones appeared in a cloud of smokes. Tsunade had five clones and Kushina had three clones. He was surprised at the result. He also did the hand signs. Suddenly the training ground was filled with 30 identical looking Arashi.

Everyone were once again had a jaw dropping expression. Who would believe that a seven year old boy could make 30 clones. Even for an Uzumaki it was huge.

"Wow so many. How much chakra do you have?" Tsunade asked while pointing to the clones. She still couldn't believe Arashi managed to out performed her in chakra quantity. She had Uzumaki and Senju blood running through her veins but she didn't had as much chakra as Arashi. She felt jealous of him. But she quickly let go of such feeling. Instead she became happy for him.

Tsunade didn't know why felt an attraction from him when she met her for the first time. She thought it was a genjutsu. But immediately discarded the idea. Their was something else going on with him. Today morning only increased the feeling more. She couldn't find the answer. She felt ashamed of herself feeling attraction towards someone of his age. He was five years younger than him. But the performance had just increased it again. She had no doubt if he was five year older, she might have considered him as a romantic interest.

What Tsunade didn't know is that due to Arashi's special attunement towards nature caused such feeling. Senju were always some what sensitive towards nature energy. Their Mokuton kekkei genkai was a bloodline limit which was closely related to nature itself. The special nature of Mokuton made them known as 'Senju of the forest'. Their dormant gene made them wanting to get close to nature. But it would be discussed more in the future.

Arashi had no idea of Tsunade's predicament. If he knew he would be feeling helpless. He was only seven years old. He had to grow up first before considering for any love interest.

Currently Nawaki was feeling extremely depressed. When he heard the shortcut to become strong, he immediately wanted to use it. He had a dream of becoming the strongest Hokage of all the time even surpassing his grandfather. But due to his small chakra quantity, he couldn't use it. He vowed to train even harder and increase his chakra reserve as quickly as possible. While everyone were amazed at Arashi's chakra level, he started his run around the training ground.

Soon the trio also started their own exercise. Tsunade herself was continuing her punching and kicking while she ordered her clones to perform chakra control exercises. She wanted to have a perfect chakra control for medical ninjutsu.

Kushina continued her run and her clones started the tree climbing exercise. She thought of completing this exercise today.

Arashi on the other hand decided to use 20 clones for reading different fuinjutsu related books and medical related books from his storage seal and the Senju library respectively. While the other clones decided to start the tree climbing exercise again.

After the changes in his body during the two days, his chakra quantity had tripled. And it had no sign of stopping. He thought it would stop after his body underwent some kind of transformation due to the circulation of nature energy inside his body. It would perhaps make his body more powerful than Hashirama and Ashura. Perhaps closer to Hagoromo's sage body but different. According to his estimation it would take him a year. But the increase in chakra quantity would slow down.

He started doing different exercises like push ups, sit ups etc. After fifteen minutes, he got memories of his clones completing tree climbing exercise. He was not surprised with the time required to complete. With his soul increased to mortal limit, his chakra control had sky rocketed. He just needed to practice whenever his chakra increased a little quickly. Otherwise he didn't need it. He ordered his clones to practice water walking with leaves sticking on his forehead. This was also completed in less time.

Later he decided to use his clone searching chakra nature transformation for each element. He wanted to learn all chakra natures. he had a feeling, his chakra elemental affinities were quite high for all five elements. He decided to check it in a later date. His clones went to the Senju library to search for relevant information.

He continued to do physical exercises. He found out that his physical limits have increased significantly. He could feel nature energy constantly circulating his body as he did more strenuous activities. After half an hour, a servant came and informed all of them to come to dining hall for breakfast.

Everyone went ahead to refresh and soon joined Mito in breakfast. They chatted while eating about their training. Tsunade informed about Shadow Clone jutsu and its usage for speeding up training to Mito to which she just smiled and congratulated them for finding out this. She gave them some tips for training. After finishing off breakfast, Nawaki went to ninja academy. The trio followed Mito to start their fuinjutsu training.

Arashi, Tsunade and Kushina had already completed their basic training. So, Mito started to describe them about some intermediate level seals and Uzumaki Style sealing technique. This technique didn't required any sealing ink to write the seals. But user used their own chakra to write the seal. This way they could use it during battles and it would not leave any kind of mark after you used it.

She told them that Uzumaki clansmen had to have excellent chakra control for using this technique during battles. Speed was also an important factor. Nobody would wait for you to complete the seal. This was a reason why only a handful of members could use it.

She reminded everyone to put extra effort on this before completing the session. Soon the trio decided to go to library for extra information. Senju clan had a big library. it almost as big as the public library of Konoha. During the waring periods they collected many different books about different fields.

Being one of the oldest clan dating back to the time of Sage of Six Paths, many important history books were also present. You could find some old books written by previous Senju clans detailing many unusual places, events that had strong impact on the development of the shinobi world. Some scrolls even contained various jutsu. But all the important scrolls like jutsus of First and Second hokage were sealed. Nobody could touch them without permission from the clan head. That means only Mito had the authority to give permission.

Arashi decided to use his clones to read medical related books while he started mediating in a quite place. He wanted to as quickly as possible complete his transformation. After that he could test his theories. Whether he could use Wood Style or if he needed First Hokage's cells for it.

He continued to circulate nature energy through out his body and hasten the process. Others were also using their clones to do some readings. Soon it was time for lunch. They continued their reading after lunch. Nobody wanted to waste time. They had heard about the meeting. So they knew they had improve their strengths as soon as possible before the war broke out.

As for joining the academy, Kushina and Arashi were informed to wait for the start of next month. New curriculums were being added and knew teachers were being hired. At the start of the next month this would be applied. So they would be joining during that time.

They were some what relieved after hearing the news. They were thinking to use this free time to advance their sealing knowledge as much as possible.

As evening approached, Nawaki also joined them. Arashi dispelled his clones. He got several memories of different sealing theories and medical theories. His clones had not looked into advanced sealing techniques inside the storage scroll. Rather he read some of the beginner level scrolls. He wanted to have all the knowledge from basics to high level. Though Mito had explained them, he wanted to know if she had left something.

He also shared the scrolls with Kushina and Tsunade. They were definitely trustworthy and the beginner level scrolls didn't contain any forbidden technique like the 'Reaper Death Seal'.

He found a scroll with 'Uzumaki Legacy Seal' written on it. But he could open the seal. It needed very advanced level of seal knowledge. Putting aside the scroll for another time, he thought he would show it to grandma Mito later. She definitely could shed some light into it.

Like this the month went by. Soon they would be joining the academy. They were some what excited to meet kids of their age. But Arashi was excited for different reason. He would be looking for potential allies most likely a Hyuga and an Uchiha. Hence he was looking forward to it.