The Next Morning
When Muramasa Shirou woke, the faint scent of flowers still lingered in his nose. His body and clothes were faintly infused with Musashi's fragrance, and in front of his half-open eyes was the delicate white skin of the swordswoman who held him like a doll in her arms.
It was the kind of scene he might have dreamed of in a past life.But Muramasa Shirou was calm. After all—he was still under seven years old. What wicked thoughts could a child possibly have?
Musashi stirred. With a transplanted magic circuit in her body, she sensed her Master's awakening instantly. Her light blue eyes blinked open, and with a lazy yawn she brushed her long hair back behind her ear.
"Good morning, Master."
Unlike ordinary Servants, Musashi couldn't draw magical energy directly from Shirou. The solidified circuit in her body was like a plug—but the socket, Shirou himself, had yet to supply power. And with less than a year until the Fourth Holy Grail War, the Grail System certainly wasn't going to hand out free energy this early.
"Morning."
Shirou brought up the Servant Panel in his system. Three changes stood out on Musashi's status screen.
First: Bond Level. It had risen from 2 to 3. Out of a maximum of 5, level 3 meant genuine affection. If a Master requested… that kind of magical replenishment, the Servant would hardly refuse. Shirou remembered Musashi's open-mindedness on the matter—"If you like each other, then it's fine." Yet when it came to himself, he couldn't help having a strangely bashful heart. Still, it seemed his childish appearance had accelerated their bond.
Second: Her skill [No-Space]. Once marked "(Fake)," it had now shed the falsehood. Musashi had truly attained the swordsman's highest realm—emptiness.
Third: Her Noble Phantasm, [Six Paths, Five Rings – Kurikara Celestial Phenomenon], had been upgraded from A to A++. Its output was now enough to rival even the [Sword of Promised Victory].
"Let's head back. Doraemon must be worried sick."
Musashi hugged him close. "You're right. I've played around enough for a day. If I get too lazy, the sharpness of my blade will dull."
"Haven't you said something like that before?"
"Of course. The sword's the same as life. Grind it too much and it'll snap. Leave it alone and it'll rust. But that balance can't just be left to nature—it depends on one's character and talent."
"…That sounds way too reliable. Not really something I'd expect from a Berserker."
Musashi chuckled. She wasn't just Japan's greatest swordswoman—she was a strategist too, author of The Book of Five Rings, divided into Earth, Water, Fire, Wind, and Sky. The last, Sky, described her personal understanding of [Void].
Pinching his cheek, she teased, "Master, you need to understand me better."
Her attainment of [Void] had changed not just her swordsmanship, but her mentality as well. She could even sever thought itself—so naturally, the [Madness Enhancement] of her Berserker class no longer bound her.
Returning Home
"I'm back."
Shirou greeted the Matou household as he stepped inside. Moments later, hurried footsteps approached. Doraemon rushed over, his round blue face creased with worry.
"Shirou! How was training?"
Shirou couldn't blame him for listening to Musashi's words. Doraemon was simple-minded—easy to fool, especially when it came to friends. No matter how often he was tricked, he never held a grudge. He always chose to trust.
"It went smoothly. Sorry for leaving you to watch the house."
"Don't worry about me! I'm fine on my own." Doraemon tilted his head. "But… where's Musashi?"
"She went to practice. Won't be back until tonight."
Having reached [Void], Musashi needed time to adapt. After dropping Shirou off, she headed to Fuyuki's mirrored cityscape, using skyscrapers as her whetstones.
Meanwhile, Shirou turned to Doraemon.
"There's something I need your help with."
"What is it?"
"It's for training. I need you to use the [Time Cloth] to reset my body back to 3 o'clock yesterday afternoon. Over and over."
"No problem!" Doraemon beamed.
They found a quiet room, and Shirou began his experiment—transplanting magic circuits into himself.
On Magic Circuits
Magic circuits are like artificial nerves inside a magus's body—the source of their magical power. In the Age of Gods, when the world was brimming with True Ether, circuits weren't even necessary. Magi could draw directly from the great Source and perform what would now be called True Magic.
But since Solomon's time, mystery had faded. True Ether vanished, replaced by diluted Ether, the so-called "fifth element." Now, magi needed circuits both to absorb ether and to connect to the magical foundation that allowed spells to function.
Quantity wasn't everything. Quality, structure, and compatibility mattered just as much. A single flawless circuit could reach heights dozens of mediocre ones never would.
Shirou himself possessed 27 circuits—a respectable number. But they were of average quality, and his inexperience left them rough and imprecise. His only edge was his unusual magical attribute.
And so, he sought a breakthrough: to use sheer numbers to force a qualitative change.