After concluding his training in the Breath of Stone, Kuguruma Natsunishi set out for the location of his third Cultivator.
This time, what he intended to learn was the swiftest of the five main breathing styles: the Breath of Thunder.
The one responsible for teaching him was a tall woman named Nikaido Mei. She was in her early thirties, wearing a simple black eyepatch over her right eye, while her left eye was a clear, pale blue. According to her, she carried a quarter of British blood.
That said, Natsunishi couldn't find a single trace of so-called "British gentlemanly or ladylike" behavior in her. His first impression was that this person resembled a female leopard poised to spring—agile, dangerous, and wild, with a touch of uninhibited roguishness.
Even though she had retired to serve as a Cultivator, she still wore the Demon Slayer Corps uniform. However, the style had been heavily modified: the sleeves were cut off at the shoulders, and the leather belt was replaced with a waist rope. She made no effort to hide her toned arms, which were covered in old and new scars and tattoos, or her well-defined abdominal muscles, which even Natsunishi couldn't help but notice.
Of course, the most important aspect was her style of conduct, which Natsunishi found excessively pragmatic, if not outright brutal.
When he first entered the Den-Shi Dojo, the building was covered in scaffolding, appearing to be under renovation. In front of the dojo, the woman who looked like the master was directing a crowd of disciples in moving lumber and tamping the foundation. The scene resembled a construction site more than a swordsmanship dojo.
Not even a minute after Natsunishi handed over Kazami's letter of recommendation, she merely glanced at it before casually tossing the paper onto a nearby pile of wood.
"An apprentice taught by that old fogey Kazami? Served as a good little boy under Urokodaki? And then hammered iron with that hard rock Matsuyama?"
She spoke very quickly, and combined with her constantly twitching knees, she looked very much like a member of a street gang. As soon as she spoke, Natsunishi realized that the woman before him was no ordinary lady.
In the next second, she moved. Nikaido backhandedly drew the Nichirin Sword from her waist and slashed directly toward his face without any warning!
"Let me see your caliber! What makes you think you're qualified to learn the 'fastest' Breathing Style?"
She's a lunatic!
Clearly marked with a green nameplate and with no personal grudge between them, who draws a blade at the first meeting?! And it was a sharpened Nichirin Sword at that.
Natsunishi's expression shifted as he immediately activated the Breath of Wind to parry.
[Breath of Wind][First Form: Dust Whirlwind Cutter]
Seeing Natsunishi operate his breathing technique, the woman's grin became even more predatory.
[Breath of Thunder][Fifth Form: Heat Lightning]
The whirlwind had barely begun when it was intercepted by a faster, more urgent, and more violent bolt of thunder. Her speed was far superior to Natsunishi's.
"Too slow!"
The female swordsman had no intention of retreating or changing her stance. Instead, relying on her much taller stature, she pressed him and his blade against the dojo wall. Although Natsunishi managed to break free from that frantic thunder by using clever leverage, she clearly had no intention of stopping there.
When Natsunishi turned back to look at her, the tall Cultivator had already assumed the starting posture for her next sword technique. She crouched very low—so low her face was almost touching the ground.
It was an Iai strike!
Lightning erupted. The blade seemed to carry golden thunder, momentarily illuminating the dim dojo. Her straight, powerful legs acted like hidden boosters, propelling her with incredible explosive speed. Rather than a sword technique, it was more like a blinding bolt of lightning splitting one's vision.
[Breath of Thunder][First Form: Thunderclap and Flash]
I can't block this.
Natsunishi's pupils constricted as all the strength in his body converged into a single point.
[Total Concentration!]
The unpredictability of the wind. The flexible flow of water. The steady solidity of stone. The essence of his past arduous training surged forth at this moment, erupting almost simultaneously with the system's bright red attack warning.
He barely managed to sidestep the blow. The blade grazed his hair. Natsunishi felt a sudden chill by his ear. If he hadn't dodged just now, while it might not have been fatal, he certainly wouldn't have escaped without a scar on his face.
Natsunishi suddenly saw the expression in her eyes. It wasn't killing intent, but a heavier, almost burning expectation.
"Master Mei, what are you doing?!"
Natsunishi shouted to stop her while parrying her continuous attacks. Instead, his words only seemed to heighten her excitement. He even saw a flush rise to her face that only appeared when she was exhilarated.
"Testing your ability, of course! Hahahaha! Everyone says you're a strong one, so naturally, you should be able to hold your own against me!"
"Look at that, didn't you just catch my sword? Good! You've got some skill!"
Several more slashes followed, sending sparks flying under Natsunishi's parries. The disciples nearby were so frightened they retreated several steps. Among them, a young child muttered, "The Master... she's gone crazy again..."
However, Nikaido Mei acted as if she hadn't heard a thing. She continued to accelerate her blade, constantly pressing Natsunishi.
"Besides, didn't you come to train in the Breath of Thunder?!"
"The best teaching is, of course, a battle at full strength! How can you fight without seeing blood? How can you get stronger without seeing blood!"
"Kuguruma Natsunishi, right? Brat, come on, look at my chest and breathe with me!"
"I, Nikaido, will teach you well! Hahahaha!"
What the hell am I supposed to be looking at?! How could I possibly learn like this?!
Natsunishi couldn't help but avert his eyes from her impressive chest.
"Be a bit more firm! Where's your grit?!"
"Showy moves—are you chopping wood?"
"Not bad, brat, your body is quite sturdy!"
The woman didn't seem to be holding back. After several minutes of high-pressure attacks, Natsunishi's stamina began to drop, and his movements started to lose their form.
But... the progress bar for the Breath of Thunder was actually rising?!
In the gaps between parries, Natsunishi saw the progress of the Breathing Style increasing at a speed he had never anticipated.
In that case, you crazy woman! Bring it on!
In the next second, Natsunishi shifted from defense to offense, merging his figure into a storm and transforming into countless sharp blades slashing toward her.
"Oh?"
The excitement and playfulness in her single eye remained, but for the first time, a flash of genuine interest flickered within.
"Finally looking like something..."
"Good! Let me measure the length of your capability! Don't let yourself be a silver-tipped wax spear, Natsunishi!"
"I won't go easy on you like those other fools."
"Don't go crying if you lose."
This woman talks so much trash...
For a moment, Natsunishi felt a sense of familiarity. It was like the extreme toxicity of "orphan" players from all over the world in a video game. However, while players might just be stubborn and foul-mouthed without matching skills, the woman before him truly possessed the capital to back up her arrogance and poisonous tongue.
She's strong.
Thunder crackled and exploded, once again entangling with the fierce winds whipped up by Natsunishi.
Late at night, on the dojo roof.
Nikaido pulled Natsunishi into a hearty conversation, completely unconcerned about whether she would disturb the disciples' sleep below.
"Don't worry about that little thing during the day! A man should be more open-minded!" She clapped Natsunishi on the back heartily and tossed him a bottle of shochu.
The mixed-race swordswoman teased, "Don't try to fool me with that 'underage' excuse! Drink!"
Natsunishi helplessly opened the bottle. The crisp scent of alcohol mingled with the night breeze. "I say, Senior, your teaching method... is truly unique."
Nikaido naturally understood his underlying meaning. She patted the Nichirin Sword lying beside her, the scabbard making a soft clatter against the tiles.
She smiled and said, "What, can't handle this little bit of pressure? And you still want to kill all the demons, and kill Muzan?"
She raised a finger and lightly tapped her right eye covered by the black eyepatch. Where there should have been a beautiful, sapphire-like eye, there was now only a lifeless patch. And there was a large old scar that even the eyepatch couldn't fully cover.
In the night, her smile faded slightly.
"Whether it's defeating the Twelve Kizuki or the Demon King himself, their fangs and Blood Demon Arts are far superior to my Nichirin Sword."
"If you can't even withstand this 'passion' of mine, how are you going to fight them?"
Are red-named monsters and green-named NPCs even the same thing?
Natsunishi took a small sip and tested the waters: "So, you really don't have a grudge against Mr. Kazami?"
"Of course not!" she grinned, her snow-white teeth glinting coldly under the moonlight.
"That old scholar who could be blown over by a gust of wind? I don't exactly hate him; I just think his teaching methods are outdated."
"He teaches a Breathing Style and wants to start the lecture from the history of the Sengoku period. By the time he finishes a set of theories, the demons would have died of old age!"
"While it builds a solid foundation, how many years does a Demon Slayer actually live? Rather than having a talented brat like you die during the foundation-grinding stage, I'd rather train you hard myself."
"Fight enough, and you'll naturally learn the Breath of Thunder."
She gulped down the alcohol boisterously, her mouth full of coarse language.
She's quite a straightforward fellow, Natsunishi couldn't help but think.
(Former [Kinoe] Rank Slayer, Nikaido Mei)