Sword skill resonance was not unheard of. But in Koken's understanding, all prior cases of sword skill resonance involved users who had been together since childhood, practicing swordsmanship side-by-side with identical training volume, movements, and postures.
Only with this level of complete physical synchronization would their sword energies resonate and merge, ultimately multiplying the power of their sword skills severalfold, even dozens of times.
As for a situation like Yusei and Kaguya's, it had never occurred. Never mind that they hadn't practiced together, just the bizarre increase in power was unheard of.
A geometric, multiplicative increase in power? This was simply unprecedented.
There were many unclear details about the underlying reasons. Why would two people who rarely practiced together produce such resonance?
But that wasn't important right now.
Koken was beaming. He only knew that one was his biological granddaughter, and the other was his disciple, practically half a grandson.
Watching Souji and Kaguya, who only stopped their argument due to Yusei's intervention, Koken laughed heartily.
"A splendid fight!"
As for the dojo that had become 'open-air', Koken didn't mind.
He stood up and approached, asking cheerfully, "Is everyone hungry now?"
Hearing the old man's words, Yusei rubbed his stomach. He really was a bit hungry.
But hunger was secondary. The main attraction was the two [Gods of Cookery] sitting over there.
Yusei's passion for gourmet food was no less than anyone's.
Senzaemon also stood up. Seeing Yusei's eyes shining as he looked at him, filled with a craving for fine food, he too laughed heartily.
"It seems our Sword Master is quite hungry! Very well, I will go prepare it now."
Yusei nodded gratefully, "Thank you for your trouble, Director."
Senzaemon didn't react much to Yusei's slightly formal address, merely smiling slightly before taking his granddaughter Erina to the kitchen to prepare.
On the way, Erina hesitated but finally voiced the doubt in her heart.
"Grandfather... that kind of exaggerated swordsmanship... does it really exist in this world?"
"Didn't you see it with your own eyes? Whether it exists or not?" Senzaemon sighed.
"This is my first time seeing it. Even Koken has never reached this level in the past... Truly, heroes emerge from among the youth."
Hearing her grandfather praise another person their age, Erina felt no dissatisfaction. Because she herself found the other party too exaggerated.
This had already reached the level of Shounen Battle Anime.
Senzaemon seemed to remember something and said to Erina, "Do not speak of today's events to outsiders. Bury this matter in your heart."
"Huh? Why?"
Erina blinked. She wasn't the type to boast to outsiders, but encountering such a major event, she really wanted to share it with Arato and hear her thoughts.
"Mysteries should not be spoken of lightly."
Leaving these words, Senzaemon entered the kitchen to begin today's cooking, leaving Erina behind to ponder his words carefully.
She didn't understand the full meaning of her grandfather's words, but the gist was that she couldn't speak of it to others.
This, she could certainly do. She possessed the God's Tongue, not a big mouth.
Dinner time arrived.
The usually sparsely populated Shinomiya main house was exceptionally lively today.
Koken, Yusei, Shiro, Kanna, Kaguya, Souji, the Shinomiya Couple, Chika, Hayasaka, and Senzaemon with his granddaughter Erina.
This filled a large table.
With Senzaemon personally cooking, tonight's dinner was truly sumptuous.
Seeing the dazzling array of dishes at the banquet, Yusei didn't rush to pick up his chopsticks.
Instead, he quietly activated his Sharingan. He currently had five skills: [Electricity Storage], [Genius], [Driving], [ALS], and [Violin Performance].
He replaced the [Violin Performance] skill, copying Kaguya's [All-Rounder (Pseudo)].
That's right... Kaguya's talent was being an all-rounder, something evident even in daily life.
She had high achievements in various fields, including tea ceremony, martial arts, music, sports, academics, etc... Among these were contents related to etiquette.
However, it wasn't a complete 'all-rounder'. For example, electronic devices... so her 'All-Rounder' attribute came with a (Pseudo) tag.
Present at the table were his parents, and outsiders. If it were only Koken, Kaguya, his parents, and other familiar people, he wouldn't care so much about manners.
But since outsiders were also present, he needed to pay some attention.
Activating the All-Rounder ability, Yusei instantly elevated it to a true [All-Rounder]. As long as it was something Kaguya was proficient in, those abilities all reached the top level.
What she wasn't proficient in, like Electronic Device Usage, he still wasn't.
There was no helping it. The usage condition for his right eye's [Fantasy Manifestation] was to strengthen or weaken a copied ability by converting it according to his own energy proportions.
But it was only strengthening or weakening, and it wouldn't create something from nothing.
So, what he couldn't do before, he still couldn't. But those things he could do were now strengthened.
The banquet began.
Koken first stated the theme was to celebrate the recovery of Yusei, Kaguya, and Shiro.
The banquet proceeded quickly. A dinner personally cooked by Senzaemon was undoubtedly extremely delicious.
However, everyone present was cultured. No one lost their composure over the delicious food.
Yusei's parents were deeply aware they couldn't cause their son and daughters to lose honor, so they were also very reserved.
Shiro wouldn't lose her composure over delicious food unless Yusei personally made it for her or fed her himself.
Kanna quite liked it, eating with satisfaction, but as a 'child', no one said anything about it.
But what most surprised the Shinomiya Couple, Kaguya's parents, was Yusei. The Kazami Family was just an ordinary commoner family, yet today Yusei displayed impeccable etiquette. This was something they hadn't expected.
Koken also hadn't expected it, but he was clearly even happier because of it.
The banquet concluded in this somewhat strange atmosphere.
Yusei went out to the balcony for some air, and Kaguya followed him.
Looking at the moonlight outside the window, with only Kaguya by his side, Yusei helplessly let out a sigh, venting his frustration.
"Eating a meal is really exhausting."
Kaguya naturally knew what Yusei was referring to. A trace of gentleness flowed in her eyes.
Looking at the moonlight in the direction Yusei was gazing, she smiled faintly.
"Yes, it is."