A/N: The first part of the chapter is a bit theory-heavy.
——
Shinra nodded and began molding and releasing sensory chakra outward. Yoji observed him silently and was surprised.
'No hand seals. I see now why Lord Third placed him on my team.'
Even Hiruzen didn't know that Shinra could use a sensory field without hand seals; the main reason he had placed him here was due to his large range—something Yoji hadn't yet experienced.
"That's good, Shinra. Now focus and attempt to expand your range. Once you start feeling strained, immediately stop," Yoji said as he began testing Shinra's parameters.
Shinra closed his eyes and, for the first time since the incident, expanded his range beyond a kilometer. It kept growing rapidly until it reached four kilometers in radius, at which point he stopped. Yoji observed Shinra closely and reassessed him in his mind.
'Four kilometers without a medium—that's the range of some sensory jōnin out there!'
Noticing Shinra had stopped, Yoji asked him, "That was very good, Shinra. If you don't mind me asking, what sensory jutsu were you using?"
Hearing the first part, Shinra sighed softly. After hearing the second, he frowned.
"Sensory jutsu? Oh, I do it the basic way, mentioned in the academy scroll."
Yoji tilted his head. "Basic way?"
Shinra nodded. "Changing the property of my chakra into a sensory type and releasing it from my body."
Yoji looked at him and smiled. "I guess that explains a bit."
"Explains what?"
Yoji grabbed a branch and began drawing diagrams on the ground to help with his explanation.
"First of all, the sensory chakra still falls under the seven chakra nature transformations—specifically Yin chakra. However, the sensory chakra is quite special in that it's almost entirely made of mental energy. If it had a similar physical-to-mental energy ratio as normal ninjutsu, then even if you molded chakra for ten days straight, it wouldn't amount to half of that range."
"The reason I was surprised is your age. Since the sensory chakra is heavily dependent on mental energy, those who are older—or who have studied, trained, or meditated extensively—naturally have more mental energy than a normal person. Though there are some individuals born with higher mental energy, like members of the Nara clan."
Seeing the scribbles on the ground, Shinra thought, 'I see. So the reason for my large range is my actual age combined with some talent in sensory techniques.'
If Shinra's combined age from both lives were considered, he would be in his late twenties. While that was significantly older than his current physical age, it was still far from enough to explain such high mental energy on its own.
"Alright, next up—Inumaki, come over here. Let's test your parameters as well. Since you're an Inuzuka, I'd guess your sensory ability is related to smell, so let's determine the range and intensity of what you can detect."
The process of testing sensory jutsu varied greatly due to the wide range of variables involved with each sense.
"Good. Although your range isn't large, your sensitivity to chakra signatures is very commendable. However, your pup covers for your weakness in range, though his sensitivity is weaker than yours."
"Yoshimaru. His name is Yoshimaru," Inumaki said quietly.
"My bad, my bad. Welcome to Team Eight, Yoshimaru," Yoji said, realizing he had touched a nerve.
"Next up is Hyori. I already have a rough idea of your parameters from the previous test, but just in case you feel left out, I'll have you do the same."
For a moment, Hyori's eyebrows twitched. It seemed their new sensei was a bit quirky at times. After recording the parameters of Hyori's Byakugan, Yoji called for them to gather around him.
"Since today is our first day, I won't go too deeply into advanced sensory jutsu. I'll explain the general idea. Most sensory techniques fall into one of two modes: skimming or scanning. Skimming prioritizes range over depth, while scanning does the opposite—depth over range."
"There are advanced techniques that can enhance sensitivity, such as using a medium, but I wouldn't recommend attempting them without supervision. Otherwise, you might end up with brain damage."
Shinra's expression darkened slightly at that.
'So using the earth as a medium back then was the reason I collapsed. That damned scroll didn't mention such a thing—it only said it would increase my range. If I ever find the author of that scroll, I'll make sure to share some of the pain I went through.'
After finishing the explanation, Yoji tossed the branch aside.
"Alright, since there's still some time left in the day, let's skip the boring stuff and show me your combat skills. Since it's your first time, I'll give you three minutes to form a plan."
The trio looked at one another and nodded. Three minutes later, they began moving toward Yoji.
Hyori activated her Byakugan and adopted the Gentle Fist stance, while Inumaki leapt back into the trees, disappearing into the shadows.
'Hyori and I don't have the chemistry to work together on the physical front yet. In fact, my involvement might cause her to make mistakes. The key to this plan is whether Inumaki succeeds—but ambushing a jōnin sensor… is it really that easy?'
Yoji blocked Hyori's attacks effortlessly, all while keeping an eye on Shinra and Inumaki.
'Inumaki is hiding behind a tree not far from here, standing still with Yoshimaru. Shinra is constantly circling the opposite side of Hyori. Whenever I counterattack, he rushes in to intercept, making sure he doesn't interfere with her movements. Good tactics against a chūnin—but what will you do if I raise the level?'
Yoji broke through Hyori's Gentle Fist with ease and kicked her into a nearby tree. He then vanished from sight and reappeared beside Shinra, striking him in the right side and sending him flying.
While airborne, Shinra pulled out a ball and slammed it into the ground, creating a smokescreen. From within the smoke, three shuriken flew out in quick succession.
Yoji smirked and avoided all three despite the low visibility.
From within the smoke, Shinra emerged with lightning coating his hands and engaged Yoji at close range.
Yoji was surprised by Shinra's attack speed but still avoided every strike with ease. He deliberately left a small opening in his defense—only to be surprised when Shinra didn't take the bait.
From the corner of his eye, he saw Hyori rushing toward him as Shinra moved in as well.
'They're finally attacking together.'
Before he could intercept them, the ground beneath him cracked as a pair of hands attempted to pull him down. Yoji leapt into the air, narrowly avoiding Inumaki, who had emerged from underground.
'Does he already know how to disguise chakra signatures? Not bad. They really came up with a solid plan in just three minutes. I may need to revise my training plans after this.'
Yoji was genuinely impressed by their teamwork—yet before ending the session, he felt a chakra signature flying toward him from the trees.
He tilted his head slightly, narrowly avoiding a lightning-clad kunai that streaked past his cheek.
'Who did that?'
He looked down and realized none of his three students could have attacked from that angle.
From within the trees, a Shinra clone stood beside Yoshimaru—it was the one who had used Lightning Flow on the kunai before throwing it.
"He managed to avoid it midair?"
Upon landing, Yoji immediately used the Body Flicker using a single one-handed seal and reappeared behind the trio, knocking them all down with ease. He then located the clone and dispelled it with a single strike to the neck.
'So it really was a shadow clone… When did he form it?' Replaying the fight, Yoji identified only two possible moments.
'Either after the smoke bomb—or before the spar even started. Did he switch places with Inumaki from the beginning and disguise himself using the Transformation Jutsu?'
He touched his cheek, recalling the lightning-coated kunai. 'Looks like I should treat them to something good after such an entertaining day.'