[A/N : The fanfic has crossed 100k words!]
The next morning, when he woke up, something left Fujin completely shocked! His body had no pain whatsoever. He speculated, 'Does this training also heal the body in some way? Or is it something else? More importantly, is this safe? I need to consult him asap!'
Renjiro appeared at the Training ground at 5am as usual and asked the genins to begin their workout. However, today, Fujin said, "Sensei, I have some queries."
Understanding what query he'd have, he replied, "Alright. Hoka, Mieko, you two begin your workout. Fujin will join you two soon."
Hoka left wondering what query Fujin had, while Mieko left begrudgingly as Fujin got to skip out on the workout a bit.
Renjiro then looked at Fujin and asked, "Is it about the quick healing?" Fujin nodded.
Renjiro answered, "It's a side effect of this training. Since you infuse Chakra in your body, it ends up activating each and every cell of your body. This will increase your passive healing and also reduce the amount of time you need to recover from fatigue or exhaustion."
He then smiled a bit and continued, "There's actually a few more advantages of this training. It'll increase your stamina, and more importantly, your chakra reserves."
Fujin's eyes widened on hearing that. He quickly asked, "Isn't it too much of a hax?"
Renjiro smirked and said, "Not really. The passive healing, while good, isn't really groundbreaking. As for Chakra increase, it is only visible when you start this training and if your chakra reserve isn't already very high.
So while you may see a huge boost to your chakra and stamina in the next few weeks, later on, the effect won't really be that obvious."
That killed Fujin's excitement a bit as he sank into his thoughts, 'Oh, then it's not that big of a hax. But still pretty good though. After all, the very requirement to learn this style is having high chakra. And if the effect of learning this style was a boost to your chakra reserve, then it just doubles down on that advantage!'
He looked back at Renjiro and asked, "Is there any harmful side effect to using this technique?"
Renjiro was a bit surprised by that question. After all, any other 10 year old genin would just be too happy with such a huge buff. He remembered that he himself had been lost in delight when he had learnt this technique. He answered, "Don't worry, this is a very old Senju technique. There are no harmful effects. In fact, considering the long lifespans of my clan members, it might even be having a good effect on your health."
Hearing the answer, Fujin let out a sigh of relief. Renjiro looked at him and said, "If you have no more questions, begin your workout. Your teammates have left you behind considerably."
Fujin thanked him and started the workout. While he had increased the pressure from the seal a lot, infusing chakra meant that exercises were actually easier for him.
Of course, that wasn't foolproof. After all, the moment his chakra ran out, was the moment hell began feeling real to Fujin!
Later that day, Fujin talked with Renjiro about the issue of Chakra running out during the Morning workout. But Renjiro just smiled 'innocently' and said, "You have enough chakra to be able to go through the whole morning workout without running out. It's just your control that is lacking. So if you don't want to run out of chakra during your workout, train and improve your control."
Fujin gave a deadpan look to his teacher's innocent smile. He could bet all his money that he was laughing at his misery.
The training continued in a similar manner for Fujin. After 3 days, he finally managed to last the entire morning workout without running out of chakra.
On day 7, he finally managed to contain all Chakra in his body properly. He still didn't reach zero wastage, but the amount of chakra leaking out now was very negligible.
These 7 days, however, had blown Fujin's mind. The result of this training was phenomenal!
He muttered to himself in disbelief, "Just 1 week of this training has increased my chakra reserves by 50%!"
In addition to the chakra increase, Renjiro made Fujin increase the pressure on the training seal from day 3 onwards. Right now it was up to 40%.
The next month was spent on properly mastering chakra control for the Senju Taijutsu style. At the end of the training, Fujin could finally freely control his chakra and employ it in a spar against Renjiro.
This training increased his Chakra by another 35-40%. In just over 5 months since he graduated, Fujin's chakra reserves had a four-fold increase! His thoughts were, "Incredible! I now have more Chakra than even Genki! And he was an Elite Chuunin for 4 years at least. Damn, I really want to test out my Ninjutsu right now."
Unfortunately, he was still denied permission to train Ninjutsu. With all 3 students training intensely, Renjiro didn't take any missions for a couple of months.
Renjiro spent a few more weeks drilling all the basics of Senju Taijutsu style in Fujin.
The process of increasing pressure from the training seal continued during this time. At that moment, it was at 55%! Fujin always had to keep infusing his body with chakra while doing rigorous training or sparring. Otherwise, this pressure would slow him down a lot. And if he was doing some normal activities, like walking or running or resting, then the pressure shouldn't really bother him much. By this logic, Renjiro had Fujin maintain that pressure all the time.
Finally, one fine evening, Renjiro watched a tired Fujin panting on the ground. They had just finished another one of their spars. He smiled and said, "Great work kiddo. You have finally got all the basics down properly."
Fujin just nodded. Clearly, he was too tired to answer back. Renjiro smiled and said, "Let's end here. Take a rest and take tomorrow off."
Hearing that, Fujin suddenly looked up. There were almost tears in his eyes! He thought, 'Finally!!'
Renjiro chuckled at his reaction and then flickered away.
Fujin rested a bit and then dragged himself across Konoha to his house while thinking, 'Finally! 2 months, and not a single day's break. Hoka and Mieko got off days saying that they needed to master their clan jutsus. But for me? I didn't get even a single session off!'
He went to sleep while complaining about the unfairness in his heart.