Become stronger.
In Shinra's mind, there were three points that he needed to grow stronger: nutrition, physical improvement, and knowledge.
Nutrition was easy as Shion never lacked money, and she could get him the best food and nutrition foods to make Shinra's body stronger.
The physical improvement was also easy, especially—
"You want Ozu to train your physical ability?" Shion asked weirdly.
"Can he?"
"Okay." Shion nodded since, despite losing to Shinra, she knew well that Ozu was one of the most knowledgeable men in the world and had much research on the muscles, so without a doubt, Ozu was a good teacher for Shinra to grow stronger muscles.
Still, the third was knowledge, and this was also easy for Shion.
"You want me to collect all the powerful martial artists' fighting videos, and learn another martial arts, too?"
"Can you?"
"I can, but what's wrong with your martial arts?"
According to the judgment of all of her subordinates from the record of Shinra's fight against Ozu, all of them had come to the conclusion that Shinra should have mastered Aikido, a martial art that was mastered by her former lover.
If possible, Shion wanted Shinra to continue on with this martial art, so when Shinra defeated that former lover by her former lover's most prized martial art, she could somehow feel comfortable, especially when she still felt annoyed when she was cheated in the past by her former lover.
"I am about to reach a threshold of my mastery, so I need to see other martial arts to develop it further."
"....." Shion and Tomoko.
"Really?"
"Really."
Shinra knew that most people would say that it was better to master one technique till the end, than having to learn many techniques yet master none.
This should be the case if he were a normal person, and he would just learn one martial art, but he was a member of the Uchiha Clan, with just a glance, he could learn something in near-perfection instantly, so why should he be stubborn to just master one technique instead of hesitating to increase his arsenal, so he could face any situation, right?
Whether it was the Niko Style or the Koei Style, they were all powerful, and frankly, it was enough for him to become the strongest with two martial arts, yet why couldn't he make one himself?
In the end, a martial art was created by someone who suited the style of the founders, but it didn't mean those martial arts were suitable for him, so he thought to make one himself that suited his liking, and because of that, he needed more knowledge, information, and learned more.
What was the best way?
Naturally, by studying, so while there was a time before the main event, why shouldn't he do his best to grow stronger?
"Okay." Still, Shion agreed with his request. "So, what do you want to learn first?"
Now, when this question was asked, Shinra wasn't sure what to learn.
The martial art is divided into two types: unarmed and armed.
The unarmed was divided into several types of strikes and grappling. Those two would also be divided further, such as focusing on the punch, kick, knee, or elbow on the strike type, and throwing, joint lock, pinning, and trapping on the grappling type. If one went further, it could be divided further by how one used their footwork, as several types of footwork existed.
Still, frankly, Shinra knew that it was just a waste of time for him to learn all of that since no matter what, his opponent had the ability to destroy a city or two with ease.
Itachi could even summon Susanoo, the special ability of the Manekyou Sharingan, a skeleton-like figure that could smash everything in its path.
So, instead of an unarmed martial art, which he could learn by using the "Eyes of Insight" of Sharingan, it was better for him to learn—
"Armed martial arts?"
"Can I?"
"...you can, but no weapons are allowed in the Kengan Match, you know?"
In the Kengan Match, all the fighters had to be unarmed, and while some were cheating by using weapons, they would be discovered immediately and disqualified. Some might be able to cheat by using a trick or two, but the strongest had never relied on tricks, but on pure martial arts.
Shinra also didn't deny that, yet the strongest one, especially in the world of the supernatural, wasn't due to the martial art, but an overwhelming power that could crush anything instantly.
Even the purpose of a martial art was created in the past so that the weak could fight against the strong.
As for why it was the East that had developed most martial arts, it was because their bodies were weaker than those of Westerners, whose diets were mostly based on proteins instead of carbs.
So, instead of learning unarmed martial arts, he might just as well have learned how to use a weapon, since using weapons sometimes was better than being unarmed.
He might be hardly able to use those arms in this world, but in another world?
"I don't mind. Just think of this as a precaution."
"Okay, then. I will get teachers for you for all of that."
"Thank you."
By then, Shion didn't waste her time and left since she was the chairwoman of the Koyo Academy Group, so of course, she was busy.
"You are going to learn the weapons of this world?"
"Yes, the weapon in this world is fearsome."
As a ninja, they mostly fought by throwing weapons or cold weapons such as a sword, but in this world, everyone used firearms, so of course, Shinra planned to learn how to use them, and if possible, he also wanted to learn how to make a bomb.
Bomb.
It might appear simple, yet it was destructive, and even in the world of Ninja, many often used it, but by using an explosive tag instead of a normal bomb in this world.
If Shinra couldn't fight his opponents, who got stronger due to their bloodlines, innate powers, and talents, then he would fight them by using technology.
Still, before that, he looked at Mikoto and asked, "How about you? What do you want to do?"
"Eh?"
"Won't it be too boring for you to stay at a house all the time? I think that you can become a teacher at Shion-nee's school."
"A teacher..." Mikoto also felt that this wasn't bad, and felt quite good, too, since she could understand the situation of this world better, and also, as expected, it would be boring to stay at the house all the time, especially when he went to school, work, and training.
While Mikoto could stay by his side all the time, frankly, Shinra felt that it was weird, especially when he had to focus on growing stronger.
As for being Shion's bodyguard or secretary, Shinra felt that it was too much since he knew that Shion's working time was unregulated, and Mikoto might be forced to stay till midnight, depending on the situation, which he didn't want to since he didn't want to be apart from her too long, so being a teacher was good, especially when it had clear work hours, and more importantly, Shion should have an all-female school, which was good for Mikoto to work at.
"But what can I teach?"
"..."
That was a good question. What could Mikoto teach?
After all, she had just come to this world; she had no knowledge of this world, nor even common sense, so could she even become a teacher?
In the end, Shinra gave up and thought of another idea. "Do you want to become a housewife for me?"
Mikoto blushed shyly, yet she nodded. "Okay."
Thus, their cohabitation life started, and as expected, their life was extremely lewd.