Leisurely days always pass quickly.
In the blink of an eye, ten days had passed since Yamada moved into the Butterfly Mansion.
Tomorrow was the special Hashira Meeting personally convened by Kagaya.
And today was also the day Yamada's nichirin blade and uniform were to be delivered.
Near noon.
A weirdo wearing a ridiculous mask with wind chimes tied to his head, carrying two long cloth bundles, stepped aggressively into the gates of the Butterfly Mansion.
"Where is that bastard brat named Tanaka Yamada?! How dare you make me, Haganezuka Hotaru, personally come to deliver the sword! Get out here and receive your blade!"
Accompanied by an extremely arrogant roar, the famous troublemaker of the Swordsmith Village and one of the most skilled swordsmiths, Haganezuka Hotaru, strode in grandly.
Yamada heard the commotion and came out from the backyard.
Shinobu and several little girls followed behind curiously.
"You're Tanaka Yamada?"
Haganezuka Hotaru pointed at Yamada, his tone extremely arrogant. "Listen up! This sword is a masterpiece I forged using that top-quality scarlet ore you brought back, spending ten full days and nights without sleep! If you dare to break it in battle, I'll come for you with a kitchen knife in the middle of the night!"
"You talk too much."
Yamada couldn't be bothered with this sword fanatic's roaring and walked forward, tearing open the cloth bundle.
Inside was not only a set of black Demon Slayer Corps uniforms but also a brand new nichirin blade in its sheath.
Because Yamada was used to the feel of the Kusanagi Sword, the style of this nichirin blade was not made with the traditional katana curve. Instead, it was forged into an extremely straight sword style according to his requirements.
"Quick, draw it! The nichirin blade is also called the Color-Changing Blade, it changes color according to the user's characteristics!" Hotaru leaned in excitedly, staring intently at the hilt.
"Let me see what color yours is!"
Even Shinobu nearby showed a curious gaze.
As far as she knew, Yamada did not use any known Breathing Style, so what color would his blade turn?
Yamada gripped the hilt and applied force with his wrist.
Clang!
A crisp sound of drawing the sword rang out.
The snow-white blade shimmered with a cold light under the sun.
Immediately after, when Yamada's palm contacted the hilt, the Lightning-attribute Chakra within his body instinctively surged through his arm and into the blade.
An incredible scene occurred.
The originally snow-white blade was instantly dyed an extremely deep pitch black from the base upwards.
But unlike Tanjiro's pure black, on Yamada's black blade, purple lightning patterns emerged, spreading like blood vessels. Faint currents of electricity crackled on the blade, emitting a heart-palpitating aura of violent destructive power.
"Black... black base with purple patterns?!"
Hotaru was dumbfounded, even the mask on his face went crooked. "And the blade comes with its own lightning?! How is this possible! This doesn't fit common sense at all!"
Yamada gave the sword a casual flourish, feeling the good conductivity of the nichirin blade, and nodded with satisfaction.
"It seems Chakra can also be conducted through the nichirin blade. Although the material isn't as sturdy as my Kusanagi Sword, it's enough to deal with those small fry who aren't worthy of my main weapon."
"Is the Hashira Meeting tomorrow?"
Yamada sheathed the extremely flashy nichirin blade and looked toward the direction of the Demon Slayer Corps headquarters in the distance.
"It's time to go meet that group of so-called strongest swordsmen."
—
The night was deep, and the guest room in the Butterfly Mansion was so quiet that only the occasional chirping of insects could be heard from outside the window.
Yamada sat cross-legged on the tatami, two blades laid flat on the floor in front of him.
One was Kusanagi Sword: Modified that came with the system's starter pack. It was pitch black, a straight-edged single-blade sword, indestructible and possessing a demon-slaying trait.
The other was the Thunder-Patterned Black Nichirin Blade that Hotaru had just delivered during the day.
"The conductivity of the nichirin blade is indeed good. Scarlet Ore, a mineral that has absorbed sunlight, is naturally compatible with my Lightning Chakra."
Yamada reached out and stroked the faintly flickering purple thunder patterns on the nichirin blade, but his brow twitched slightly. "However, the durability is too poor."
No matter how superb the forging techniques of this world were, the physical limits of Scarlet Ore remained.
It might be sharp enough for an ordinary swordsman, but if Yamada poured in his full Chakra to perform Chidori Sharp Spear or a higher-level Lightning Release shape transformation, this nichirin blade would most likely shatter because it couldn't withstand the violent energy.
In a true life-and-death struggle, once a weapon breaks, even a momentary opening is enough to be fatal.
'System, can you integrate the material properties and conductivity of this nichirin blade into the Kusanagi Sword?' Yamada called out the system in his mind.
[Ding! Host's requirement detected.]
[Plan generated: Decompose the 'Thunder-Patterned Black Nichirin Blade' (Premium Scarlet Ore material, high-tier Chakra conductivity) and perfectly forge it into 'Kusanagi Sword: Modified'.]
[After fusion, the Kusanagi Sword will retain its original 'Absolute Indestructibility' attribute, while gaining extreme lightning Chakra conductivity and inheriting the thunder-pattern visual effect.]
[This fusion requires 880 dimension points. Confirm fusion?]
'880 points? Confirm fusion.' Yamada gave the command without hesitation.
As soon as he spoke, a brilliant dark-golden light surged from the void, completely enveloping the two blades on the floor.
There was no deafening sound of hammering, nor any earth-shattering phenomena. After only a few seconds, the dark-golden light quietly dissipated.
The nichirin blade that had been lying on the floor had vanished into thin air, leaving only a straight sword lying quietly in its black scabbard.
Yamada reached out to grip the hilt and drew it with a "clink."
The transformed Kusanagi Sword's blade remained that textured dark black, but along the edge of the blade, several winding purple lightning patterns, like blood vessels, had appeared.
Just holding it in his hand, Yamada could feel as if the sword had become an extension of his own arm. With just a thought, the Lightning Chakra in his body could flow smoothly from the hilt to the tip of the blade without any resistance.
"Not bad, this can even increase the power of my Lightning Release by twenty percent."
Satisfied, Yamada sheathed the new Kusanagi Sword, placed it by his pillow, and fell asleep.
...
The next morning.
The sun was bright and the breeze was gentle.
Bang! Bang! Bang!
A rough knocking on the door woke Yamada from his slumber.
"Yamada! Get up quickly! The sun is already high in the sky, do you think we're going on a picnic today?!" Shinobu's somewhat impatient voice sounded from outside the door.
Ever since her disguise was ruthlessly torn away by Yamada a few days ago, this sharp-tongued butterfly had completely let herself go in front of him.
She had thrown her mask of a gentle onee-san to the winds, replacing it with her original tsundere and sharp-tongued nature.
The sliding door was pulled open with a "shing."
Yamada walked out yawning, already changed into the brand-new black uniform of the Demon Slayer Corps.
However, he wore it very casually. The three buttons on his chest weren't fastened at all, and the open collar revealed his firm collarbones. He had a pure black haori draped loosely over his shoulders.
"It's so early, are you trying to nag me to death?" Yamada glanced at her.
Today, Shinobu was still wearing her iconic butterfly-patterned haori, but perhaps because of Yamada's comment yesterday about her being a "short-tempered, sharp-tongued little brat," she was rarely wearing a bit of light makeup today, making her look bright and moving.
"You... is that how you wear the uniform? The discipline of the Demon Slayer Corps is going to be ruined by you."
Seeing Yamada's disheveled and careless appearance, Shinobu frowned.
She subconsciously stepped forward, stood on her tiptoes, and reached out to help him fasten the buttons on his collar.
The distance between the two instantly closed, to the point where they could even feel each other's breath.
Yamada lowered his head slightly, looking at Shinobu who was within reach. Her cheeks had a hint of a healthy blush, and her serious eyes held a bit of disdain, but her movements were surprisingly gentle.
"The way you look now is quite like a virtuous wife seeing her husband off." Yamada blurted out.
Click.
Shinobu's fingers suddenly stiffened, and a button she had just fastened was almost ripped off by her.
"You... what nonsense are you talking about!"
Shinobu jumped back two steps as if she had been electrocuted. Her originally fair cheeks instantly turned red to the roots of her ears, and her purple eyes were full of embarrassment and panic.
"Stop flattering yourself! I'm just afraid that your thug-like appearance will lose face for the Butterfly Mansion when you see Master!" Shinobu glared at him, trying to act calm.
She turned and left, her pace even faster than usual. "Hurry up and follow me. If you're late, I won't help you collect your corpse."
Looking at her back as she almost fled in panic, Yamada chuckled, grabbed the Kusanagi Sword from the table, and followed her leisurely.