Next morning, Genki showed up at Fujin's house at 8 am. After picking him up, they went to a training ground. Fujin saw that a middle-aged man, probably in late 20s or early 30s was waiting. He noticed that the man had Yamanaka crest on him. He thought, 'Should have guessed. In Konoha, they are the best sensors.'

Genki approached him and said, "Yo. This is the kid I was talking about. Fujin, he is Shin. He was my classmate. He is a special jounin. He'll be giving you tips on how to become a sensor. He may seem grumpy at times, but don't worry, he is a very kind person."

Fujin nodded, "Good morning Shin sensei"

He noted that Shin, who was already looking a bit mad at Genki's introduction, seemed even more grumpy after he greeted him.

Shin angrily said, "Damn you Genki. Not only do you give such a shit introduction but now are also trying to pull me into being a sensei?"

He then looked at Fujin strictly and said, "Kiddo, don't ever call me Sensei."

Fujin wondered, 'Why is everyone so strange?' while Genki asked mockingly, "Damn, why do you have to be so grumpy so early in the day?"

Fujin acted to show he was nervous and asked, "So what do I call you?"

Shin thought for a few seconds, and then put up a smile on his face, with his eyes almost sparkling, and said "Call me Shin aniki." His face looked borderline creepy.

Fujin's expression immediately became entirely plain and almost blurted out, 'Why don't I call you old geezer?'

Genki facepalmed and scolded, "Stop being creepy. Let him call you sensei!"

Shin sighed in disappointment and replied, "Alright, leave it."

Then looking at Fujin he said, "Alright kiddo, first let's see how talented you are in becoming a sensor. If your talent is very poor, then I won't be teaching you and you shouldn't waste your time on it either."

He first lectured Fujin a bit about what sensors do and how. Then instructed Fujin to sit in a meditative pose and told him how to sense his chakra field. It took nearly half an hour for Fujin to sense his chakra field. The instructions were very helpful.

Shin then tested Fujin's chakra field a bit. After some testing, he concluded that Fujin's chakra field had a radius of 7.3 metres.

Shin commented, "7.3 metres, not bad. An average ninja has a chakra field of 4 to 5 metres. In my Yamanaka clan, we train our youngsters in becoming a sensor if their chakra field exceeds 7 metres, while for other Konoha Shinobi, the minimum requirement is 5.9 metres. However that is just the bare minimum. Quite a few in the Yamanaka clan had their chakra field exceed 10 metres before they started training to become a sensor. I myself had a radius of 10.6 metres. So while you can become a sensor, you'll have to do a lot of hard work. So are you sure you still wanna to train to become a sensor?"

Fujin processed all the information quickly and nodded. Shin said, "Alright, I'll guide you. However, the process of training to become a sensor is quite complicated. We will need proper training facilities. I'll take you to the place where Konoha sensors are trained. You will start visiting there daily at 10:30 am from tomorrow onwards."

Genki nodded at his former classmate. He looked at Fujin and informed, "Lord Hokage will have your seals ready by tomorrow. Report to his office tomorrow at 6 pm." Fujin nodded and said, "Thank You sensei"

He then accompanied Shin to the training facility. The location was slightly away from the residential areas. It was in the middle of one of the many mini-forests in Konoha. Fujin memorized the location and then took his leave.

Next day, Fujin reached the training facility at 10:28 am. He saw that Shin was already there. On entering, Fujin saw that there were a lot of rooms in the facility. The facility was mostly empty with very few people actually being there. However Fujin noted that quite a few rooms were occupied. Shin said, "These rooms isolate everything outside it. And also have seals that can eliminate all sound and smell in the room. So you'll have to entirely be dependent on your ability to sense."

Fujin paid attention while Shin was explaining it. He thought, 'I see, this makes sense. I suppose this is where most of Konoha's sensors train. I guess other trainees are occupying other rooms. I don't recall properly, but I think Konoha also had a facility that aided it to monitor the whole border of the village to look for intruders or something along those lines, though it was only shown in Shippuden and not in part 1. I wonder if that facility is also in here, or is it someplace elsewhere?'

Shin led Fujin in one of the rooms. The room was very dark. All walls were painted black. The room was pretty big too. On entering, Shin explained Fujin how to train to be able to sense with only the help of his chakra. He said, "A blindfold will be placed on you, and after the seals are activated, all sound and smell in the room will be eliminated. After that, a few objects will be placed in the room. These objects have a small amount of Chakra sealed within them in a manner that it can be detected by sensors. So your job will be to detect these objects. We will start by placing the object 3 metres from you, and later increase the range to 5 metres and then to 7 metres. Once you are done with it, then I'll teach you how to increase the size of your chakra field."

Fujin understood and thanked him. He started the training. The training continued till 12:30 with him having no success at all. At that time, Shin ended the training. He said, that they'll daily train here for 2 hours and also gave him a few tips in order to make some progress. He also had a few words of encouragement for Fujin as he said that these things can't be sensed in a day and to not get very upset.

He also provided Fujin with a small cubical object. He said, "This is one of the objects that I had asked you to sense. You can temporarily borrow this to practice at home. Though you won't be able to block your sense of smell and sound, however it shouldn't matter much as you don't specialize in either of those. So just try to practice with your blindfold on. Maybe ask someone else to place the square down somewhere after you have put the blindfold and sat in your meditative posture. That way you won't know where exactly the cube is beforehand. However, don't practice for very long."

Fujin understood all what Shin said and nodded. He then thanked Shin and left for his home. With the academy over, he now had 7 additional hours he could use for training. The training at the facility, travelling to and fro and lunch took slightly less than 3 hours. Fujin allotted all the remaining 4 hours for chakra sensing training temporarily.

In the Hokage office, Hiruzen looked at the custom made seals on his desk. He sighed softly while thinking, 'Konoha's edge in Fuinjutsu is fading fast. With the annihilation of the Uzumaki clan and the passing away of Mito sama, our progress in Fuinjutsu had almost come to a standstill. Kushina and Minato had just started to make progress, but they died too young. Now it almost took 2 whole days to get such a simple seal custom made for Fujin.

The request is still quite surprising though. Genki did say that the kid was diligent, but asking for such seals at such a young age is incredibly rare. Only a few geniuses among the clans usually train with this. However even they start at a later age in most cases. I do recall him glancing at Genki first before asking for the prize. I guess Genki was the one who suggested the idea to him. I guess I should have a nice chat with him when he visits me in a few hours.'

At 6pm, Fujin reached Hokage office and entered after knocking. He greeted respectfully while bowing his head slightly, "Good evening lord Hokage"

Hiruzen was impressed by it, he thought, 'Well atleast his manners are very good.'

He said, "Look up. Here are the seals you requested. This seal is a special seal designed by our village, it combines the features of a few basic seals in order to create a perfect tool to help train the bodies of our Shinobi. You can manipulate the amount of pressure the seal puts on your body freely. The pressure is applied on the whole body."

Fujin nodded and said, "Thank you Lord Hokage." He then looked at the seal placed in front of him. The seal was engraved on a square shaped paper. He thought, 'There is just one seal. I thought that there would be four or more seals to be applied on various parts of the body like the 4 limbs and so on. I guess this seal is much more advanced. Sigh, I can't analyze this seal then. Still, it's better that I have to place this seal on myself and no one else has to make the seal on my body. This way the chances of someone creating issues will probably be lower. That said, I'm not supposed to know much about Fuinjutsu.'

He then looked up at Hokage, and asked, "Lord Hokage, how do I use this seal?"

Hiruzen replied, "Just place the seal on your chest. It should stick to your body. The seal is reusable, so you can remove it and put it again if you ever wanted to. But don't ever give this seal to anyone else."

Fujin replied, "Yes, Lord Hokage. But how do I increase or decrease the pressure caused by the seal. Also how much pressure can be applied by the seal?"

Hiruzen chuckled at the curiosity of the youngster in front of him. He replied, "Just focus your chakra on the seal. It's similar to how you focus chakra on the leaf during leaf concentration exercise. Then you can decide whether to increase or decrease the pressure and it'll be done automatically. As for the maximum pressure, it can apply a lot. It is equivalent to wearing a body vest of 100kg, 50kg weights on each leg and 25kg weights on each arm."

Fujin was shocked with those numbers. He nearly cursed out, 'Bastard, shouldn't you say that first!' However he maintained control of his emotions. In order to keep up his act, he gulped and showed a bit of fear on his face.

Hiruzen looked at Fujin's expression and smirked internally, thinking, 'Well, this will ensure that he always uses that seal very carefully and doesn't harm himself with it.'

After that, Hiruzen talked a bit with Fujin. He tried to understand what caused Fujin to require these seals. He also asked about his daily life, whether his apartment is comfortable, whether he ate properly and so on. He also made Fujin try controlling the pressure in his presence. He also explained some tips and precautions. For instance, he said that while sleeping, Fujin should always deactivate the seal. He also cautioned Fujin against using the seal while sparring or fighting saying, "if you get used to it, then you will find it hard to properly control your movements when you deactivate the seal." At the end, he praised Fujin's performance in the exams and let him go.

After leaving, Fujin thought, '250kg huh. I really wanna know if anyone actually uses it all. I do wonder how much weight Lee carried. The number was never mentioned in the series.'

While leaving the Hokage office, Fujin had already activated the seal. In front of Hiruzen, he kept the pressure very low. However, after leaving the Hokage building, he increased the pressure. He increased it to a level where it put a decent amount of strain on his body, while still being able to bear it.

He ran all the way to his home and thought, 'Finally, even this simple run was a challenge! Though I will probably have to reduce the pressure a bit in order to be able to complete the workout routine Genki provided. I suppose I'll have to test for a few days in order to get the pressure right. I can track my progress too, as I will know the percentage of max pressure applied by the seal.'

He also thought about what all Hiruzen told him and focused on 2 points, 'He specified to not use the seal while sleeping and fighting. I suppose not following the first one ain't an option. As for 2nd, I can understand his point of view and concerns. If I do it, then trying to fight without that pressure will cause plenty of issues. Of course they can be fixed with some work, however if in the middle of a fight, it'll be deadly. However Kaguya did have a high gravity dimension. So I should try to learn to fight under high pressure too. But there's no need to do it now. Maybe later on I could build a gravity chamber and practice there. That might be more effective.

Still, I gotta admit that this seal is very good. It applies pressure throughout my body. The pressure on my legs is more than on my arms. Even my back feels the strain. I guess the seal is made in a way that every muscle is properly exercised. Which would result in proper development of the whole body. There won't be any cases of some muscles being developed more and others being underdeveloped. I guess Hiruzen left out the specifics, not expecting me to understand them. This method is much superior to the weights Lee used. I guess I really need to be thankful to Genki. Though, this does make me wonder why these guys haven't given the seal to every Konoha shinobi. Is it that hard to produce?'

Ending his train of thoughts, Fujin started to meditate.