Fifteenth quickly ran to the adjacent room and began watching through the small window with the strongest formation-reinforced glass capable of withstanding several full-power blows from an average Chunin.
Kenshin calmly headed to the ring, along the way removing all clothes with telekinesis and pulling on various exo-suit components. In literally two seconds he was in full combat readiness and took the Nara clan's defensive stance.
Ichiro saw the attack signal and immediately rushed at Father, striking full-force with a kick to the head. Fifteenth didn't even notice the moment of attack but clearly saw Father put up a block with both arms and stop the powerful kick.
Dust under Kenshin's feet scattered in all directions, and at the point of collision between arms and leg hundreds of small lines flashed for a fraction of a second. The blow was stopped without much trouble.
Kenshin smiled satisfactorily and tried to sweep Ichiro's supporting leg but failed. An incredible battle began, inaccessible to Fifteenth's eyes. Two silhouettes exchanged several blows per second and constantly flew.
Although Kenshin's physical capabilities didn't allow him to react and move as fast as a full-fledged Chunin, his accelerated perception allowed him to notice the slightest muscle contractions in a fraction of a second and predict the opponent's action in advance.
After several minutes the winner was still not determined. The spar reached a deadlock. Kenshin didn't have the same strength and speed as Ichiro, so he couldn't trap and defeat him. Ichiro in turn didn't have such incredible perception, and his father always minimized damage.
The exo-suit had undergone incredible changes, but it was still not enough for Kenshin to defeat Chunin. Kenshin's movement speed was barely at peak Genin level, and strike strength even lower. All those several dozen blows Kenshin barely landed on his opponent were no more painful for Ichiro than a ten-year-old child's punch to an adult man.
"Enough." Kenshin declared, understanding the spar had reached a deadlock. Ichiro could easily defeat him if he used ninjutsu or Sharingan, so Kenshin didn't delude himself about his strength.
"Oh, Father, your suit is just something…" Ichiro groaned, rubbing his lower jaw where Kenshin's leg had so successfully landed.
"Nonsense. Another fifteen minutes and the energy would run out. The suit needs improvement…" Kenshin sighed, not very pleased with the result.
*****
The entire next week Kensebbe occupied only with improving his exo-suit and finally by evening of the 226th day finished the planned work. He squeezed the maximum from available formation creation knowledge and got a suit that gave him peak Genin strength and speed while allowing him to withstand full-power Chunin blows. Kasumi still sent him into small flights with her strongest strikes, but even so he could resist a bit.
"Ichiro, Third, and Fourth. Tomorrow you're coming with me. Get a good night's sleep—we have a combat mission ahead." he declared during dinner, shocking all sons.
Without explaining anything, he turned and left the dining hall, heading to his wives. The hardest part was ahead.
"WHAT?! No, you're not going anywhere!" Kasumi declared, shocked by his plan.
"I must conclude the contract. No one but me can do it—or did you forget I'm an excellent empath?" Kenshin countered.
"Don't talk nonsense, Nakayama Kenshin. You're not going anywhere, I won't let you!" Natsumi supported her friend, angry at her husband.
"Kenshin, dear, maybe change your mind…?" Aya said gently and hugged him from behind, laying her head on his shoulders and tenderly kissing his neck.
"Girls, understand—we need to develop. Without combat experience the children will be nothing more than punching bags. We need to register as mercenaries and complete a test mission. Kasumi, you yourself said they don't accept everyone, and without a good negotiator everything could fail." he said, stroking the tender legs of his sitting wives.
"Then I'll go with you. I'm the strongest fighter in our family, and only I can protect you." Kasumi declared, refusing to let her beloved go.
"No, that won't happen. Although your belly isn't visible yet, you're already pregnant and won't go anywhere. Besides, Eighteenth needs a mother. God forbid if something happens to you." Kenshin said with a sigh and again stroked the tender thighs of his third wife.
"And if something happens to you, that's okay?!" she snapped.
"Nothing will happen to me. You should have understood that from all those spars. I can always escape from a peak Chunin, and you know the last resort rules."
"But…" Kasumi began but was stopped by Kenshin's authoritative order.
"Enough! I'm not going to discuss this topic with you anymore. The guys and I are leaving on a mission tomorrow, and the most you can do is wish us luck." he declared and stood from his chair, heading to his office now located on the second floor.
"I need to finish preparations. Don't disturb me unless absolutely necessary."
*****
In the morning of the 227th day the atmosphere in the Nakayama family home changed from cheerful and calm to tense and sad. The girls were offended at Kenshin and tried several times to talk him out of this risky venture, but he was adamant.
That morning everyone had breakfast at one table, but it didn't add joy to family members' faces. Kenshin's wives feared the terrible prospects of this campaign, and his sons were mostly upset that they would stay home while Father and older brothers were in danger.
"In my absence Kasumi will be responsible for family protection. If an enemy appears, everyone must obey her." Kenshin declared and took a sip of apple juice. He felt unusually relaxed and behaved completely calmly.
"How confident are you in this mission's success?" Kasumi asked, pushing her plate aside. She had no appetite at all.
"Ninety percent that everything will go normally, and ninety-five that at least half will return alive." Kenshin answered calmly, not afraid to say such things aloud.
Hearing such an optimistic forecast, Kasumi relaxed a bit, while the rest of the family tensed, especially Aya. She couldn't imagine there was a chance someone wouldn't return again. Thinking of her second son, tears welled up in her eyes. She silently approached Kenshin, sat on his lap, and buried her face in his broad shoulder.
Kenshin silently began stroking her back. He didn't know what to say in such a situation, so he was silent. Everyone else also stopped eating, and each thought about their own.
After breakfast everyone quietly dispersed, and Kenshin with Ichiro, Third, and Fourth began packing. Everything was ready from yesterday, but Kenshin checked everything thoroughly again.
Each was dressed in an analog of the exo-suit with many formations. The sons' suits weren't as complex as Kenshin's, because creating one such suit required several days of jewelry work. Their suits could withstand several dozen blows from a peak Chunin and were tuned to a specific type of damage. All elemental technique attacks as well as strikes to the back and head were met by formations. Forearm strikes stronger than an average Chunin were only slightly absorbed to save energy. Impulse from blows wasn't dissipated for the same reason.
With new knowledge, Kenshin only slightly increased battery capacity and reached a dead end. He needed revolutionary knowledge to overturn all previous ones and somehow allow storing tens of times more energy to withstand Jonin-level blows in the future. But for now it was just dreams.
After everything was finally packed, Kenshin allowed older sons to say goodbye to their mothers, and then when they left the door, stayed alone with the girls.
Aya had tear-stained eyes, while Natsumi and Kasumi had very sad faces. He hugged all three and said: "I'll definitely return. No need to worry so much. Aya, girl, when I return we'll eat your favorite ice cream all day and swim in the pool, okay?" he whispered with a smile to the crying girl.
"Promise?" she sobbed. Her mind tried to grasp any straw for a bit of calm.
"Promise." he said and hugged each girl again, then left without looking back.