Leaving the terrace where we had our lunch, Kushina led us back toward the training grounds at first, but then we took a turn that went deeper into the village, before she cut sideways through residential terraces, down a pair of narrow paths that twisted between stone walls and moss-covered metal pylons.
"Do you even know where we are heading?" I asked, making her glance at me like I asked if the sky was pink or something.
"Do you want a good place or not?"
"Fair. I'm just asking." I shrugged, raising my hands in defeat.
"I said, I know one. So, follow me, that's all. Do you think I didn't have places memorized when I wanted to be alone? Be happy I am showing it to you two dorks, dattebane!"
"Renji..." Minato warned me, and I just shrugged a second time.
"I'm just afraid that without her, we will never find our way back... this village is a maze..."
I wasn't lying; it was a damned maze, and the farther we walked, the quieter it became. The sounds of Uzushiogakure in the end completely faded into the background, until all I could hear was the wind and our own footsteps.
"This place," I muttered, glancing around the empty landscape, "is either going to be perfect for training… or perfect for hiding a body. You still angry at Minato? Please don't punish me too, I even tried to let you two have some smooching time!"
"You want to die, dattebane?!" Kushina shot back over her shoulder, but didn't dare to look at us. Mostly because I could tell her ears were as red as her hair. "I used to come here to scream at the world when I was little..."
"That doesn't help my fears..." I added, but much more quietly this time around. "Minato... it was good knowing you...!"
"Shut up, dattebane!"
In the end, we emerged into a shallow clearing carved into the rock itself, half-hidden by old trees that surrounded it on all sides. With the way the 'walls' were, I could see some of their roots coming down, and how they cracked and reshaped the stone over the decades or centuries. One of them, which was a massive, twisted thing, stood at the center of this clearing, its branches arching overhead, growing to be about what...? Forty? Fifty meters tall? Damn.
"Here," Kushina said, turning to face us. "Nobody comes here because it was a training ground for Senju guests in the past, and... well, we are sticklers for tradition, so we just do not intrude on this place, even if no Senju have come to train here for a long time now."
"Incredible," Minato whispered as he looked around. "This will be perfect," he added.
Of course, you'd say that, not that I would say anything else myself, not in front of Kushina. And yeah, it was indeed perfect. Seeing him say that, Kushina dropped her bag and stretched, then pointed at us, or, Minato to be precise.
"Alright, genius. Before you blow us all up or whatever you want to do... Now you can explain what you were babbling about at lunch, dattebane! But do it... Slowly. With words that I can understand... Got it?"
"Right. Okay." Minato straightened immediately, like a student called on in class to give his report that may determine his future. "The Flying Thunder God, depending on who you ask, is a movement technique or a spatial jutsu. But that's not entirely true. It is a kind of hybrid between the two, but even then, it also has a third part, all of it derived from seals. It is a combination of multiple fields, and that's the mistake most people make when they think about it, identifying it as just one of the three."
"I can't believe it... You would know all this because you read letters from the second Hokage...? Really?" I shook my head, listening to him, making him look away, scratching his cheeks.
"I was quoting him, in fact... Anyway! It's not really about speed," he continued, "but instant relocation. The displacement happens outside normal spatial traversal, so to us, it seems fast, but, as the term suggests, it is instantaneous... In theory."
"Meaning?" Kushina prompted, crossing her arms.
"Meaning the chakra is not like when we use it to stand on water, or run at high speeds, it doesn't push the body through space, like it pushes us through air," he expressed, gesturing vaguely, trying to explain it to us. "It is used to… Um... reassign locations."
"Assigned to what?" I asked, but I was already getting an idea. I didn't read those letters, but just hearing him speak... and what he had mentioned before, I think he means that Tobirama was exchanging those letters with someone who was well-versed in spatial seals. Meaning, the chakra assignment for sure had to do with the seals that also gave Minato the inspiration.
"To a seal," Minato's eyes flicked to me, confirming what I was thinking of, "To a reference point in space and time."
"Is it like..." Kushina hummed. "How our Uzumaki seals work in many cases? We have seals that we put on containers, not for holding things inside, but to specify where things are allowed to be or what things are not allowed to enter. I can't do those formations yet, but... Like, we can set up spaces that allow certain people, let's say, a family to enter, while it would reject others."
"Yes!" Minato's face lit up. "Exactly! They had similar ideas exchanged in those letters I was reading!" With that, he knelt at the base of the tree and pulled out a brush and inkstone, beginning to draw. "The Second Hokage's mistake—"
"Whoa, whoa, buddy!" I stopped him at once, making them look at us, "Mistake? Are you saying... Tobirama Senju... one of the greatest minds of his era... made a mistake?"
Of course, that made Kushina laugh, watching how Minato's face went red, suddenly feeling conscious, and looking around as if Tobirama's spirit would jump out of thin air to hit him on the head.
"Well, not a mistake, but a limitation..." He corrected himself in the end, "He was tying activation and displacement together. Even he realized it, thus these letters. It was a complex sequence that had to be recalculated every time. He wanted to alter that, so he shared some of his markings in hopes of improving them, getting feedback from the Uzumaki he was communicating with. For the Hokage, these calculations and, thus, the chakra they required, were, of course, marginal. He could do it, he was fine... but teaching it to others? Nobody else could do it."
"And you want to separate them," I said, seeing his point.
"Yes," he replied instantly, smiling at me. "The mark should do the thinking, I mean, be something that doesn't need recalculations, because its position, no matter where it is, is easily accessed."
"I don't get what you mean, but," Kushina crouched beside him, "From what I understand, your seal has to do two major things for something like that," she said, suddenly looking like an actual Uzumaki. I was... surprised, in a good way. "It has to: Identify itself for the caster, and then it has to persist, or others could remove it. Not to mention degradation..."
"I will have to work on that part, yes... But for now," Minato nodded rapidly, already sketching up a rudimentary seal.
As he did, I stepped back a little and activated my Sharingan, taking a look at his work with different eyes... literally. Minato's chakra flowed cleanly, and although I couldn't see it like a Byakugan did, I could tell where the lines were forming, infusing it into the seal he was drawing up. Honestly, it looked like writing, but there were no symbols or words that matched it, almost how they would look on his future signature kunai.
"Stop!" I said suddenly.
"?!" Minato froze instantly, looking at me, "What?" he asked.
"That part," I pointed at it, my Sharingan fixated on a certain section, "Your loop there... You're closing it too early."
"Eh?" He frowned, looking at it, "But if I don't—"
"No, he is right." Kushina nodded suddenly, "Even if this is not a normal seal, and I'm not a master, I know enough... Loosen it, because chakra flowing through it may create an interference and cancel it out."
No longer asking anything, Minato started over, this time around, loosening the loop when he got that part, while I kept watching.
"Still wrong," I muttered, watching the way his chakra was reacting to his drawing.
"Ugh..." Minato grimaced, not because he was making mistakes, but because he realized this won't be as easy as he thought it might be. Duh! "You can see it where?"
"A bit," I said slowly, furrowing my brows and straining my Sharingan, "My eyes realize it as a jutsu, and it tries to read and decipher it. When that feeling stops, it means you made a mistake, and it's not the right way to do it."
That got both of them to look at me, blinking their eyes, looking at my red irises.
"Uchiha." The two snorted at once, shaking their hands.
"Stuff it!" I chortled, continuing, "Tobirama designed this thing specifically to battle against our eyes. I guess he never realized that, although we can't see the instant transmission, we can still read the seal's application. Minato, you will have to make sure you don't let people see you putting down the marks in the future."
"Yeah..." Minato murmured, "That's a good point, but, at least with you, I can make it work quicker than just doing trial and error runs over and over again!"
"Lucky you!" I laughed, keeping my eye on the half-completed seal.
In the end, Minato had failed with the second version... so he tried again... and again. Again. Aaaaand... again. Until we finally had one of his seals ready.
"Okay!" he said, breathing out and looking at it on a simple paper. "Then that's it."
"It looks stable," Kushina said after a momentary pause. "Seals all come from different shapes or forms, well, not really, because all of them are circle-like. But the circles are made up from sections like this. What I am saying is that this looks... unique?"
"Well, it is, isn't it?" Minato asked as he swallowed in excitement. "Let's put it on the tree," he said, standing up.
"Okay, this is the mark, yes?" Kushina asked, pinning the paper to the tree. "Does this act like a... receiver?"
"Um!" Minato nodded, "As I said, this one is to ease the calculations. This receiver, this mark, is the one that the user has to lock onto. Wherever it is, it contains spatial and temporal coordinates, meaning it tells the user where it is... at any and all times. Now, I will have to create the other half of the seal, which only needs activation, and the two halves become one. That moment will initiate the transfer and bring them together, finishing the technique! Pretty simple, really."
"Yeah," I glanced at Kushina, "Simple."
"Dattebane..."
Of course, with my eyes' help, Minato inscribed the other mark carefully, for now, attaching it to the hilt of a kunai. As per his idea, it was small enough to be transferred, and he wouldn't dare try with anything... bigger. Or living.
"Alright," he said, examining it and holding it up, "Moment of truth!"
"No need to stand on ceremony," I patted him on the back, "Go for it!"
With that, Minato threw the kunai, without hesitation, activating it the moment it left his fingers. There was no big flash or any type of sound, it simply wasn't there anymore... and then...
Thunk!
The kunai appeared against the tree, embedded shallowly in the bark, wobbling a little before falling down, unable to pierce it completely. But... who cares about that?! I simply burst out laughing almost immediately.
"You did it!" I barked at him, patting his back, "You absolute madman, you did it!"
"The momentum didn't carry as I expected it would," he murmured after his initial happiness disappeared, "The transfer for some reason had stripped it of half of its speed..."
"Come on, cheer, dattebane!" Kushina smacked his arm with full force, "You teleported a weapon across space for the first time in history, and that's what you focus on?"
Finally, he was grinning, beginning to laugh himself, and as he did, something else occurred to me...
Yeah. He did... But... I don't remember him ever doing that in the show...