Arima and his mother rushed to Hashirama's house, only to find the once-mighty "God of Shinobi" looking frail and gaunt.
The room was thick with the scent of herbs, a clear sign he had just endured a brutal battle.
Arima's heart filled with worry as he looked at the once warm and gentle man now lying weakly in bed.
At that moment, he felt utterly powerless. He had always helped strangers wherever he could, yet when it came to the suffering of someone so close to him, he found himself helpless.
Hashirama perked up slightly upon seeing his grandson. Though the passing of his friend Madara had left a deep ache in his heart, the village and their clan still needed him.
Forcing a smile, he said to Arima.
"Little Arima, your Grandpa and Grandpa Madara fought for a whole day and night in the Valley of the End, so I'm just a bit exhausted.
No need to worry. I'm still hanging in there and I'll have plenty of time to spend with you."
Seeing how hard his grandfather was trying to comfort him, Arima could only nod along, smiling as he replied, "I've already mastered hand seals. Soon, I'll be able to start learning jutsu."
Hashirama found comfort in his grandson's obedient and thoughtful demeanor.
Sensing his grandfather was still quite tired, Arima said his goodbyes and promised to visit again tomorrow. Hashirama could only nod weakly in response.
On the way home, Arima remained silent, overwhelmed by a growing desire for strength, strength to protect his loved ones.
From then on, his training intensified. Aside from daily visits to his grandfather, every spare moment was devoted to physical conditioning and chakra control.
He even spent 1,000 virtue points to boost his hand seal speed to five seals per second.
About three months later, Hashirama was just barely able to get out of bed. The last battle had taken a serious toll on his body.
Arima pushed himself harder than ever.
He saved another 1,000 virtue points for the future awakening of the Sharingan, and invested the rest into various abilities, some to improve his understanding of jutsu, others to simplify the hand seal sequences.
Time passed quickly, and by the ninth year of Konoha, Arima turned six.
In the last year and a half, he had nearly mastered every E-rank and D-rank jutsu in Tobirama's arsenal.
He even managed to pester Tobirama into teaching him most of the C-rank and a few B-rank jutsu.
His progress with Wood Release was especially promising, and he had already learned Wood Clone Jutsu.
During that time, Hashirama had mostly recovered, though the damage to his body's foundation seemed beyond repair.
Arima could tell that despite his cheerful appearance, his grandfather's vitality wasn't quite what it used to be.
Hashirama also noticed that ever since falling ill, his grandson had become obsessed with gaining strength.
Still, he was relieved that Arima remained kindhearted, always looking for ways to help others, still the same sweet little Arima.
Both Hashirama and Tobirama had watched Arima grow over the past two years, and he never once disappointed them.
Arima's hand seal speed outpaced most of the Jonin in the village. In battle, this meant he would always have the upper hand.
Like an insatiable sponge, he absorbed every jutsu he encountered with astonishing speed, quickly mastering them.
Sometimes he even devised ways to reduce the number of required hand seals.
The two brothers were often amazed by him, and so they taught him everything without reservation.
One day, as Arima was heading out for his usual training, his mother called out to him with a smile.
"Arima, if you had a little sister to take care of, would you still go out training by yourself every day? Or would you spend time with her instead?"
Her sudden question puzzled Arima. His father had died in battle long ago, and he lived with his mother. Where would a sister come from? Still, he didn't voice his doubts.
At his age, he was already mature beyond his years, more like a ten year old than a six year old. Years of good deeds and interactions with others had made him insightful and experienced.
He simply smiled sweetly and said, "Mother, you forgot, I can use Wood Clone Jutsu. It's not like Shadow Clones that vanish with a single hit."
Naomi felt a pang of sorrow seeing how grown-up her little boy had become.
She knew how hard he trained. Ever since Hashirama was injured, he had taken everything upon himself.
She knew her son was disciplined and mature, with a strong sense of responsibility.
Sometimes she thought that if he had a little sibling trailing behind him, maybe his childhood would've been a bit happier.
And now, the opportunity was finally here.
She said cheerfully, "Arima, don't you remember? Two years ago, at your Grandpa's place, you promised Grandma Mito you'd look after her granddaughter, your little cousin.
The whole family is at the hospital waiting for your baby cousin to be born."
Arima's expression turned a little complicated. He had been planning to train today. Still, even if she was technically a cousin, she would be his little sister all the same.
And if she was family, then of course he'd treat her with extra love and care.
That thought made him happy. He suddenly found himself looking forward to how this little sister might change his life.
Naomi was delighted to see how quickly her son embraced the idea of having a sibling to care for. Her little boy really was a natural sweetheart.
Together, they headed to the hospital, where a large crowd was already gathered outside the delivery room.
Not only was Hashirama there, but Tobirama and even his students had shown up.
When the crowd saw Arima arrive, the atmosphere brightened.
Other than learning from Hashirama and Tobirama, Arima spent most of his time in rigorous training .
His clones wandered around the village helping others whenever possible.
Though still very young, he had already displayed a vast arsenal of techniques, a flexible fighting style, and superior chakra control.
His hand seal speed and chakra reserves even surpassed most Chunin. Within a few years, he'd surely qualify as a Jonin.
Koharu was especially fond of him. She adored this sweet, mature boy. The moment she saw him, she ran over and hugged him tightly.
Arima felt a bit overwhelmed by her enthusiasm, but she smelled nice, so he let her do as she pleased, chalk it up to another good deed.
Hashirama called him over and smiled warmly, pride shining in his eyes. Arima had never let him down.
He pulled out a necklace identical to the one he had once given Arima, handing it to him.
"Arima, keep this safe for now. When little Tsunade grows up, give it to her as a gift from me."
Arima sensed the gravity behind his grandfather's words but said nothing. He accepted the necklace as a silent promise to protect Tsunade with all his heart.
Just then, the delivery room door creaked open. Mito emerged, cradling a tiny baby girl in her arms.
Arima gazed at the sleeping Tsunade in her swaddling clothes. Her adorable face melted his heart. In that moment, he silently vowed to protect her with everything he had.
From that day on, visiting his little cousin became part of Arima's daily routine. He'd play with her and keep her company no matter how busy he was.
Time flew. By the thirteenth year of Konoha, Arima was ten years old.
On his birthday, he passed the Jonin-level evaluation given by his two mentors, becoming the youngest Jonin in Konoha's history, and the youngest ever to achieve such a rank.
As a birthday gift, Hashirama handed him his personal summoning scroll. Arima signed a summoning contract with the slugs of Shikkotsu Forest.
Four years had passed. The once precocious boy had grown into a true shinobi.
His strength far surpassed that of ordinary Jonin, and his skill with ninjutsu was exceptional, almost rivaling Tobirama.
Over the years, he had developed numerous B-rank and A-rank techniques, and even one S-rank secret technique.
Now that he was a full-fledged Jonin, he had access to the forbidden and secret arts Tobirama had told him about.
The one he anticipated the most was the Flying Thunder God Technique.
In Konoha, Arima had become something of a celebrity.
Almost everyone in the village recognized the small-statured Jonin. Ever since he began his "one good deed a day" mission six years ago, he had made countless friends and connections.
Tsunade was now four years old. The adorable little girl loved sticking close to her Arima-nii. She was his cute, clingy little tail.
She understood that her big brother was a training maniac, but whenever he had time, he would always come play with her, making him the best brother in the world.
Tsunade was proud of how much her brother was admired in the village.
But once, she overheard Koharu say that Arima was far too handsome, and many girls had a crush on him.
Tsunade didn't know exactly what "having a crush" meant, but she understood one thing, if she didn't keep a close eye on her brother, one day he might leave her for some other girl.
Then he wouldn't bring her treats or toys anymore, or play with her at all.
So, as she grew older, she became even more attached to Arima.
Still, one thing made her really happy, Arima would take her to the gambling halls.
Even if she lost all the money he made from missions, he didn't mind. He'd just smile and say, as long as she was happy, that's all that mattered.
Sometimes Tsunade wondered why her brother loved training so much.
Eventually, she couldn't hold back and asked Hashirama in secret.
She still remembered his answer vividly.
"Your Arima-nii wants to protect his family. He wants to protect everything he holds dear. And little Tsunade, you are one of the treasures he wants to protect most."
After that, Hashirama burst out laughing with joy.
To him, all his efforts over the years were finally bearing fruit. Even if his time in this world was drawing to a close, he could go peacefully.
That day, Tsunade came back from playing and immediately saw a familiar figure.
She knew right away, her Arima-nii had returned from a mission. She sprinted toward him and threw herself into his arms.
Arima held her gently. He had just completed a B-rank mission, but before even going home, he came to visit his grandfather and bring Tsunade a bunch of fun souvenirs.
He chatted with Hashirama about the mission and even joined him for a few rounds of gambling to lift his spirits.
On the way home, Arima watched the falling leaves and murmured.
"It's late autumn already... the land is turning barren and the air is growing colder. Wearing too much makes training harder."
Though he was bundled up warmly, he couldn't shake the chill creeping into his heart.
That evening, after returning home, he felt inexplicably uneasy. He couldn't pinpoint why.
Lying in bed, sleep eluded him.
Then came a knock at the door. He threw on a robe and opened it to find one of Hashirama's personal guards.
And from him, Arima heard the words he feared most.
"Lord First Hokage would like to see you for…..one last time."
The news hit Arima like a bolt of lightning. Swallowing his sorrow, he quickly dressed and rushed to that all too familiar place.