Konoha.
It was the scorching August heat, and although the Fourth Great Ninja War had officially begun, most of the battles were still skirmishes. For now, the Hidden Leaf still enjoyed a brief period of peace.
Rooftop — leaning against the railing.
Tsunade had just returned to the village. Her blonde hair was tied back in a high ponytail, and she wore a short, midriff-baring top with a mesh shirt underneath — a crisp, clean look for summer.
"Happy twelfth birthday, Nawaki."
Smiling warmly, Tsunade held out a gift as she stood across from her younger brother. Nawaki, wearing a Konoha forehead protector tied around his head, looked slightly embarrassed.
"I'm not a little kid anymore, you know. You don't have to get me anything."
Despite the words, Nawaki's bright smile gave him away — and his hands had already accepted the gift.
Tsunade chuckled at the scene.
"Come on, open it. You might like it."
She leaned lazily against the railing, watching Nawaki with a teasing smile. But hidden in her eyes… was a hint of unease.
The gift was a metal box, finely decorated. As Nawaki opened it, his face lit up with surprise.
"Wait… Sis, is this…?!"
Tsunade's soft laughter confirmed it.
"Yep. That's the First Hokage's necklace — our grandfather's."
The moment she confirmed it, Nawaki beamed with joy.
"I love it! Thank you, Sis!"
As he bounced with excitement, Tsunade casually tossed out a question:
"So… heard you're heading out on a mission tomorrow?"
Her tone was light, almost teasing, but Nawaki didn't catch the subtle shift in her voice. Still riding the high of the moment, he nodded immediately, with no hesitation at all.
"Yep! We got the assignment yesterday. We leave tomorrow. I'll be with Orochimaru-sensei."
He even tilted his head slightly with a bright smile, trying to reassure her.
Tsunade smiled back, but her eyes dimmed slightly.
Is Orochimaru involved in this mission?
She didn't know — and the uncertainty gnawed at her. Nawaki wasn't just her brother; he was the future of the Senju Clan.
The breeze carried Nawaki's laughter as Tsunade continued her playful banter.
"You know, if you'd ranked first instead of that Uchiha brat, I would've taken you as my subordinate already."
Nawaki grinned sheepishly.
"It's fine, Sis. Even if I were the top student, I'd still choose Orochimaru-sensei. But I think Uchiha Ye is going to drive you crazy."
Just mentioning Uchiha Ye made Nawaki laugh even harder, enjoying the idea of his sister struggling to handle him.
The two siblings spent the rest of the day laughing together, quietly celebrating Nawaki's twelfth birthday.
The next day, the blazing sun gave way to a sky thick with storm clouds.
As if the weather itself knew something was coming.
Konoha's front gates.
Orochimaru led Nawaki's team out of the village at speed, headed for their mission.
Not long after they disappeared, a figure stepped out of the shadows at the edge of the forest beyond the village.
It was Tsunade, hidden under the canopy of a tall tree. Her expression was grim as she clutched the scroll in her hand.
"A simple C-rank mission. Reports say a band of rogue samurai has wandered into the area… but it's wartime. Intel inside the Fire Country should be tightly monitored. There's no way such a low-level error would slip through."
"Especially this close to the village."
Tsunade studied the mission details. No matter how she examined it, nothing seemed suspicious.
If someone hadn't warned her, she wouldn't have given it a second thought.
After all, the mission only required a single day. The location wasn't far. They could leave in the morning and be back by night.
But seriously — how could a real threat get through all the Fire Country patrols during wartime?
It didn't add up.
Still, this was Nawaki. Her brother. The last of the Senju line.
She couldn't take any risks.
But instead of following the team — too easy for Orochimaru to detect — Tsunade made her move.
She'd go ahead. Alone.
Orochimaru had to move slower with his team anyway. She'd get there first.
Half a day later, in a dark forest.
Several shadowy figures darted through the trees.
A scream tore through the air.
A rogue samurai's lifeless body crumpled to the ground — his neck snapped by a massive serpent.
The snakes slithered back into Orochimaru's sleeves. He licked his lips with a twisted smile.
Behind him, Nawaki and his teammates dashed forward, energized from the skirmish.
Orochimaru murmured with satisfaction:
"Nawaki is getting used to combat. His momentum is good… just a bit longer and he'll be fully adjusted to the battlefield."
Nawaki was every bit the heir of the Senju — his chakra reserves, both in quantity and quality, far exceeded other Genin.
Once he gained some experience, he'd be Chuunin-level easily.
But just as Orochimaru smiled to himself—
BOOM!
An explosion rocked the area. Blinding flames lit up the forest, casting a fiery glow across Orochimaru's pale face.
His golden snake-like eyes contracted in shock.
"Impossible…"
Even Nawaki's teammates were paralyzed. They weren't strangers to death, but this was different.
Someone important had just died.
In the distance, the blaze continued to rage.
Tsunade stood alone in the light of the fire, her eyes filled with uncontainable rage.
"Why… why the hell is there a trap made of explosive tags here?! And why so many?!"
She had arrived over an hour earlier and hidden herself, watching the so-called rogue samurai.
They hadn't shown a single sign of trouble.
Yet she had seen it happen.
Those samurai had lured Nawaki into the trap — a trap made of explosive tags.
There was only one explanation.
The trap was set in advance.
There's no way this was a coincidence.
"Nawaki!!"
His teammates screamed in horror.
Tsunade's expression twisted as she held back her fury. She threw down a charred corpse — one she had prepared ahead of time.
Along with the necklace she'd given Nawaki the day before.
She never thought she'd need it. But now…
Whoosh! Whoosh!
Cloaked in flames, Tsunade vanished from the scene, Nawaki cradled in her arms. Behind her, the fire roared even higher into the sky.
The Legendary Sannin were not yet legends.
At this point, Tsunade was the strongest of the three. Orochimaru came second. Jiraiya was dead last.
Resources mattered in the ninja world.
Orochimaru hadn't begun his forbidden experiments yet. He wasn't anywhere close to his near-immortal state (after all, even explosive tags nearly killed him during his defection in canon).
Jiraiya had yet to master Senjutsu.
Tsunade, as the Princess of the Senju Clan, had access to resources others couldn't even imagine.