The Adamantine Sealing Chains had powerful sealing capabilities. Once an ordinary shinobi was entangled by them, there was virtually no chance of breaking free.
Moreover, when it came to tailed beasts—the nuclear weapons of the ninja world—the Adamantine Sealing Chains were especially effective.
Because of that, this jutsu would perfectly make up for Tsunade's future shortcomings.
In truth, Tsunade had the greatest natural talent among the Legendary Sannin—even more than Orochimaru.
Despite wasting so many years due to her hemophobia, she was still able to maintain strength on the level of a Kage.
From the fact that she had once laid down the four medical ninja rules, it was likely that Creation Rebirth and the Yin Seal were jutsu she had invented and mastered during the Third Great Ninja War.
Not only that, Tsunade had also systematized the development of medical ninjutsu and initiated reforms in Konoha regarding the field.
From this alone, it was clear that her talent, while perhaps not quite on par with Tobirama Senju, wasn't far off.
And with the Senju Clan's collection of jutsu, it's not like Tsunade lacked resources or talent.
What she lacked… was a reason—something to make her settle down and study.
And Uchiha Hikaru had already thought it through. No matter how much of a genius Tsunade was, she couldn't possibly progress faster than him.
As long as he was around, a "baitfish effect" would form.
Even if Tsunade tried to slack off, with Mito Uzumaki nearby as a constant example, she'd have no choice but to follow through.
'Endure now, and life will be better when you grow up.'
Thinking of that deceptively comforting phrase, Uchiha Hikaru nearly burst out laughing.
It reminded him of something his high school teacher used to say in his past life. Back then, he believed it. But once he got to college, he realized how wrong it was.
"Uncle Yosuke, I may not have anything to repay you with for now, but I can at least keep Tsunade on track with her studies."
As someone who had fought on the battlefield, Senju Yosuke knew full well that more strength meant more chances of survival.
So rather than objecting to Hikaru's proposal, he was actually quite pleased. "That'd be great! Tsunade always finds ways to slack off. She's been giving us headaches for years."
Hikaru nodded and picked up the scroll. "Leave her to me. I'll study this scroll together with her."
Senju Yosuke laughed heartily as he clapped Hikaru on the shoulder.
Hikaru's willingness to repay kindness deeply satisfied him.
After all, no one wants to raise an ungrateful brat who bites the hand that feeds them.
But of course, he was overthinking it. Mito Uzumaki had far better judgment than he did.
Back at the BBQ place, even though she could tell Hikaru was putting on a show, it was his clear, sincere eyes that truly moved her.
Having lived a peaceful life in his past world, Hikaru didn't carry the fear and aggression found in the hearts of those raised in the shinobi world.
When he brought up donating to the orphanage, the mindset he showed—thinking it was simply the right thing to do—came out naturally.
To him, doing good was just… normal.
And that kind of kindness can't be faked.
After handing the scroll over to Hikaru, Senju Yosuke only chatted with him briefly before taking his leave.
Though he no longer had to go to the front lines, there were still many things that needed his attention.
Hikaru, scroll in hand, headed to Tsunade's room and informed her that they'd be studying it together from now on.
When she heard that, Tsunade was dumbfounded. She had no idea how this situation had landed on her lap.
Of course, she'd seen the scroll before. Back then, she had tried every possible excuse to reject it, and eventually managed to weasel her way out.
Even Mito Uzumaki had let it go, agreeing to wait until she was older before bringing it up again.
So naturally, Tsunade had no intention of studying it willingly. But after a quick eye roll, an idea popped into her head.
"Hey! How about a little bet? If you win, I'll do as you say."
Hikaru immediately knew Tsunade was about to dig her own grave again, and he had no intention of stopping her.
He knew her personality. Forcing things would never work.
So now, hearing her offer, he saw the perfect opportunity.
"No problem. My wager is a month's worth of your snacks. If you win just once, I'll return them all."
"But if you lose even once, you have to study seriously for three days. Deal?"
Winning once to get all her snacks back? Tsunade was brimming with confidence—completely forgetting her past losses.
She had no sense of her own gambling luck. The worse she was, the more she wanted to play.
"Let's go, then! This time we'll play High or Low!"
She grabbed the dice, gave them a shake, and slammed the cup down on the floor.
"I call High!"
Tsunade shouted excitedly.
Standing beside her, Hikaru chuckled. "Since you picked High, I'll go with Low."
Honestly, he didn't even know how to lose when gambling with Tsunade.
As expected—Low.
Tsunade was unwilling to accept the loss and insisted on playing more.
Hikaru wasn't about to pass up the chance. The two of them hit it off perfectly and kept playing until dusk fell.
The entire afternoon passed just like that.
By the time Mito Uzumaki returned, she walked into Tsunade's room and saw them playing with dice.
At first, she thought Tsunade had managed to corrupt Hikaru.
But something was off about Tsunade's expression.
Normally, she'd be hyped when gambling. But this time, she looked like she was about to cry.
Seeing Mito, Hikaru decided to take the initiative before Tsunade could back out.
"Grandma Mito, I made a deal with Tsunade—every time she loses, she studies for three days."
"She's already lost over a hundred times. Let's just round it to a hundred."
"Can I leave the tally with you? If Tsunade refuses, can you hold her accountable?"
Mito immediately understood.
No wonder Tsunade looked like that. Someone who loved gambling as much as she did wouldn't wear that expression unless things had gone horribly wrong.
And losing time instead of money? That was a cruel twist.
Hearing that, Tsunade finally burst into tears.
She really had been planning to deny the whole thing—after all, only the two of them knew the terms.
But now it was too late. Hikaru had passed the bill to Mito Uzumaki.
She could bluff Hikaru, sure. But she wouldn't dare mess with Mito.
Realizing that she now faced three hundred days of grim, study-filled misery, Tsunade collapsed into sobs.
Still, no matter how hard she cried, Mito wasn't going to coddle her.
She'd never liked Tsunade's gambling habit. Maybe losing big this time would help her drop it for good.
And since the wager wasn't about money or objects, but something good for Tsunade herself…
Rather than feeling sorry for her, Mito would make sure she followed through—seriously.