On the 157th day, another batch of blue sage ripened, and Kenshin's sons with wives could finally afford to drink the decoction every day without worrying about shortage. Natsumi had been methodically teaching Aya for a long time, trying to awaken her chakra, and with the consumption of blue sage tea, the matter accelerated a bit. Aya felt small bursts of chakra in her lower abdomen, but there was not enough accumulated yet for "awakening" and subsequent reproduction by the body.
On the 159th day, Kenshin impregnated his wives again but did not receive the planned tenth level. A bit upset at first, he decided not to lose heart and figured he would definitely get the level after the birth of Eleventh and Twelfth.
On the 161st day, a joyful event happened. Ichiro finally awakened another tomoe in his Sharingan!
Kenshin and Aya were incredibly proud of their son, and all the others sincerely congratulated Ichiro on such a magnificent achievement. All day Kenshin conducted numerous checks of Ichiro's second tomoe and came to several striking conclusions.
First — Ichiro's vision became even sharper. His eyes allowed him to catch even those movements that the body could not react to. He began to see chakra more clearly and in detail, and the ability to memorize different techniques increased by an order of magnitude. After looking at "Katon: Hosenka no Jutsu" from Natsumi, he immediately managed to repeat this spell. Although he had already mastered it by 90%, the instantly repeated spell impressed everyone gathered, and the children born from Aya burned with desire to awaken their Sharingan, hoping they inherited it like their incredible older brother.
Second — Ichiro's spatial abilities increased again. He became able to teleport an object seven meters from the target instead of the previous five; moreover, he learned to slightly change the angle of teleported things. If earlier only the distance changed but not the trajectory, now Ichiro became even more dangerous. Throwing a shuriken at the area of the enemy's left shoulder, he could not only teleport the thrown shuriken but also slightly change the trajectory, piercing the enemy's heart.
Kenshin lamented the lack of a genjutsu master at his disposal. Natsumi knew only the simplest genjutsu dispelling methods, which were more than enough to make it difficult to catch his sons in illusion. Since all brothers were in constant mental connection, genjutsu was easy to detect and dispel. But applying competent genjutsu using Sharingan was not possible. Without a proper teacher, Ichiro would need several years to master illusions on his own, which was unacceptable.
Kenshin also lamented the impossibility of using the "shadow clone" technique. When he asked Natsumi about this technique, she blinked in bewilderment and admitted she was hearing about such a technique for the first time. According to her, there are no "shadow" clones, only elemental ones, and all these techniques are at least "B" rank, and mostly only Jonin or incredibly talented Chunin use them. After thinking a bit about clones, she mentioned that according to rumors, all Kyuubi jinchuriki can use a huge number of clones thanks to the most powerful Kyuubi chakra and 90% of the load on controlling such a horde of clones taken on by it.
Recalling that conversation, Kenshin mentally scolded Kishimoto again for distortions and sighed deeply.
"Of course Genin cannot use clones! Obviously they do not have enough chakra and abilities to separate a piece of consciousness into a separate body. A Genin's brain would burn from such overloads… I should have figured it out myself instead of relying on data seen on a laptop screen!" he thought, returning from the gym to the bedroom where two beautiful girls in transparent peignoirs were already waiting for him.
*****
The following days passed routinely; everyone did their things for the benefit of the family. Kenshin strengthened old formations and installed new ones in case of another intrusion. Now he had a solid baggage of knowledge, and he did everything to increase the chances of survival and victory in a fight even with several Chunin. Thus, disorientation formations, auditory and visual hallucination formations were installed everywhere, and many pits with reinforced stakes were dug, invisible to all outsiders at least until Jonin rank.
Aya finally managed to awaken her chakra core and became at least twice stronger. In her free time, she learned the simplest chakra manipulations from Natsumi, wanting to at least give future children additional talent points.
All of Kenshin's sons trained almost all the time and stopped drinking ordinary water, consuming only blue sage tea, and the result did not take long to appear. Seventh and Eighth quite quickly mastered walking on trees and water, and Fifth and Sixth learned to use the fireball. The power of the Nakayama family grew rapidly.
On the 168th day, Ninth and Tenth finally became adults and were sent to the gym, where their older brothers were now actively training. A few days earlier, Kenshin thoroughly took up the gym and strengthened it even more.
All punching bags and makiwara were reinforced 5, 10, and 20 times, primarily in durability and also weight, so that his sons could train on them even with increased strength and not break them with one hit. Ichiro, approaching Chunin rank, could already break some thin trees with a leg kick, so the "update" of makiwara and bags greatly pleased him.
Almost all dumbbells and barbells were also reinforced and made heavier. The heaviest barbell now weighed one and a half tons, and no one could lift it. The weightlifting record was expectedly held by Ichiro, easily lifting 700 kilograms. The strength of the eldest son multiplied by speed incredibly impressed Kenshin. Ichiro could punch small pieces of stone from cliffs with his fists without significant consequences. Kenshin assumed that at the current level, Ichiro could break a small one-meter stone boulder but would severely injure his hand.
From Kenshin's observations, physical durability in this world did not keep up with strength at all but was still terrifying. In the current state of Ichiro, shuriken thrown by Kenshin from 30 meters could not seriously harm him and only stuck a few millimeters into the skin. But a kunai strike was still effective, only for Chunin-level shinobi — the speed of ordinary people was absolutely not scary. In numerous tests, Ichiro saw all of Kenshin's movements even without Sharingan, while Kenshin barely noticed how Ichiro standing behind him suddenly appeared behind his back.
Training of Ninth and Tenth was taken over by Third and Fourth. At the moment, Ichiro was the strongest and most talented of the sons and had no time for simple chakra mastery training, so this responsibility fell on the younger brothers.
Ninth and Tenth were a bit upset, but Kenshin ignored this situation and realized that sooner or later, with the increase in the number of children, stratification in status would form anyway, and not necessarily the older ones would be superior to the younger. He understood that an "ordinary" child from Natsumi could not compare with a child from an Elite Jonin or Kage-level kunoichi.