For an ordinary swordsman, identifying the specific style of someone else's Breathing Technique is no easy feat.
In their eyes, various sword techniques are essentially just slashes. Even if a strike breaks the sound barrier, it remains a matter of pure physical damage. There are no special effects. Only after reaching a certain level of mastery can one perceive that distinct temperament and realm within another swordsman's strikes and wind—for example, the gentle and inclusive nature of Water, or the frantic and free spirit of Wind.
If one's own level is insufficient, they can at best use their experience and eyesight to guess which major school or derivative branch a person might follow. But to accurately identify a derivative style at a single glance? Unless they happen to practice the exact same technique, it is impossible to distinguish them based solely on breathing frequency.
Take a Demon Slayer using a very nimble sword style, for instance. An onlooker seeing a few moves would have no way of knowing if the user was employing "Fog," "Flow," or some other specialized breathing like "Flower," "Ice," or "Frost."
This was even truer for the Sound Breathing practiced by Uzui Tengen. This particular technique had been born quite recently; Tengen had even coined the name himself.
He truly wondered how this Kuguruma had recognized it and called it out so precisely. What if he had changed the name to "Music Breathing" or "Rhythm Breathing"?
Wait, Nikaido must have told him! The ninja's mind raced before settling on what he thought was the correct answer.
As for that girl's Breathing Style... he probably deduced it through his superior eyesight and store of knowledge.
As expected of a genius with the spirit to master multiple Breathing Techniques and fuse them together. The ninja's thoughts spun, already inventing justifications for Kuguruma Natsunishi's insight.
Kanae, on the other hand, didn't overthink it. She simply felt that Kuguruma Natsunishi was exceptionally well-informed.
"My Flower Breathing wasn't taught directly by a Cultivator, though it is indeed a derivative of Water Breathing," the girl said, leaning forward slightly with an apologetic smile. "After passing the Final Selection, I stayed at the Butterfly Mansion for a while. It was during that time that I had the privilege of studying the notes left behind by the first Flower Hashira in the archives. I taught myself through trial and error, so regarding experience in creating one's own style... I'm sorry I can't be of much help to you, Kuguruma-kun."
Kuguruma Natsunishi shifted his gaze to the ninja.
"So it still comes down to the flamboyant Lord Uzui?" A smug grin appeared on the ninja's face. "Correct. My Sound Breathing is indeed developed based on Thunder Breathing. After all, while the plain Thunder Breathing is powerful, it lacks flair..."
Kuguruma Natsunishi's eyes were filled with doubt: ≖_≖
"Fine, the main reason is that it was difficult to coordinate with my shinobi tools and combat rhythm."
With that, Tengen began to explain the differences between the two styles to Kuguruma Natsunishi. Having reached LV.3 in Thunder Breathing through his own "hard work," Kuguruma Natsunishi now possessed a solid understanding of the style. He could follow the gist of Tengen's abstract descriptions.
For example:
"Though not as fast as Thunder Breathing, it is still extremely swift."
"It uses high-speed rotations to trigger my gunpowder-laden tools, allowing for flamboyant, festival-like consecutive slashes."
"The techniques rely on eyesight and hearing to capture the rhythm of the music, thereby completing one's own musical score."
...
Translated roughly: Thunder Breathing focused more on explosive power, using ultimate-speed thrusts or flashes—or straight-line high-speed slashes after a feint—to eliminate demons. These were the hallmarks and advantages of Thunder Breathing.
However, for Uzui, who required long periods of infiltration and excelled at tactical maneuvering and probing, those traits were somewhat impractical. Furthermore, the Thunder Breathing taught by Nikaido was, in the end, a samurai's way of fighting. It didn't account for poisoning, launching sneak attacks, using hidden weapons, throwing bombs, or swinging two massive cleavers to hack people down.
Rigidly studying and using Thunder Breathing and its associated sword forms would mean completely abandoning Uzui's decade-plus of rigorous shinobi training. For a man of his immense talent, combining a Breathing Technique that enhanced physical attributes and explosive power with ninjutsu was the optimal solution.
He had traded the ultimate focused slashes of Thunder Breathing for the more flexible, tactical, and skill-based Sound Breathing that pursued fluid, continuous attacks. And according to Uzui, aside from his self-created Breathing Style, he had a trump card—a super finishing move. However, up until now, no demon had ever forced him to use it.
Kuguruma Natsunishi curiously pressed him on what this killing move was, asking if he could pull it out right now to let everyone have a look. He was rejected.
"This is a secret of the God of Flamboyance. How could I show it so easily?"
Kuguruma Natsunishi: "If you won't say it, you won't. I bet it's just a larger dose of black gunpowder anyway."
Uzui's temple twitched: "..."
"By the way," Kuguruma Natsunishi suddenly leaned in, his eyes shining, "can you teach me a few ninjutsu moves? The kind that spits fire or releases electricity? If not... lend me a few bombs to play with?"
Uzui: (*▼︿▼)#
This brat has no respect for the God of Flamboyance!
The dishes were served one after another, and the three began to chat as they ate. For the most part, it was Uzui and Kuguruma Natsunishi discussing things, while Kanae held her hot tea, head tilted as she listened, occasionally chiming in with a comment.
From the Cultivators who taught them, to the cruelty of their first Final Selection, to the troublesome demons they had each encountered—they fully exchanged information and expanded their collective knowledge.
Once the initial awkwardness faded, Kuguruma Natsunishi picked up a sake cup to drink with the flamboyant man. After a few cups of sake, Uzui began to boast about a particular flamboyant battle where he used the explosions and rhythm of Sound Breathing to toy with an enemy.
Kuguruma Natsunishi listened silently, his eyes fixed on the skills hovering over the man's head.
[Thunder Breathing LV.2]
[Sound Breathing LV.1]
[Ninjutsu LV.7 (Exclusive Skill)]
His fingers unconsciously brushed against the rough surface of his teacup. As Kuguruma Natsunishi watched Tengen narrating with animated gestures, a small corner of his heart stirred. If this guy dies someday, it would be a real shame.
"Hey, Tengen."
Kuguruma Natsunishi suddenly spoke, interrupting the other's enthusiastic story.
Uzui: ?
Kuguruma Natsunishi didn't answer directly. He reached out his right hand, lightly pinching the edge of the wooden cup with his thumb and forefinger. With a slight exertion of force...
Snap.
With a soft sound, a piece of wood was cleanly torn from the wall of the cup, like breaking a crisp cracker.
Kanae blinked in surprise. The ninja raised an eyebrow. "What are you doing? Showing off your finger strength?"
"No." Kuguruma Natsunishi held the wood chip, slowly rolling it between his fingertips. "I just want to talk to you about something. Your physical strength, combat literacy, killing techniques, ninjutsu, tools—even the Sound Breathing you created—these are your advantages and specialties."
Kuguruma Natsunishi used the small piece of wood to tap the intact side of the cup. "It's like the walls of this cup. It carries your upper limit."
Uzui: ?
Are you hinting that I'm a blockhead, or are you calling me a broken cup?
As a ninja who lived over a hundred years ago, had no formal education, and spent his life immersed in combat, he wasn't particularly good at deciphering such indirect metaphors. On the side, however, Kanae vaguely guessed what Kuguruma Natsunishi was about to say.
Kuguruma Natsunishi picked up the teapot and slowly poured water into the broken cup. The wooden cup filled quickly, and then water began to trickle out of the jagged gap, soaking the tabletop.
"It might fill up fast, but once the water level exceeds a certain limit, it starts leaking much earlier than an intact cup."
"Your advantages allow you to make a very tall and sturdy cup. Perhaps you can even pour water in very quickly." He pointed at the gap where water was trickling out. "But the development level of your Breathing Technique is insufficient; it is the shortest plank at the bottom of your barrel. The monsters you're encountering now have stats and mechanics that fall within the range your 'cup' can quickly hold. That's why you fight flamboyantly and appear to have room to spare. But what about later?"
Kuguruma Natsunishi looked up. "Further down the line, the strength of monsters will grow exponentially. For instance, the Twelve Demon Moons, who serve as elite mobs."
Uzui: "Twelve Demon Moons?"
Wait, didn't your Cultivator teach you anything? Oh, it was that lunatic Nikaido. Never mind then.
"In short, they are demons stronger than the Nine Hashiras. If the speed at which your cup holds water can't keep up with the speed at which they pour it in, the only result is..."
He gave the wooden cup a forceful push. Even more tea splashed out. Insufficient skill multipliers would become an insurmountable numerical chasm in the late game.
[Guidance LV.2] (Proficiency +37)
Kuguruma Natsunishi was momentarily stunned. Just talking like this... can trigger a skill?
Across from him, the flamboyant smile on Tengen's face had vanished. He stared at the leaking, broken cup, his fingers unconsciously tapping on the table. He understood the logic, of course. It was just that no one had ever put it so visually. Moreover, it came from the mouth of a youth who was younger than him, practiced more Breathing Styles, and—most importantly—was stronger than him.
"Ah, Kuguruma-kun!"
The girl's urgent, soft cry interrupted Tengen's contemplation and cut off Kuguruma Natsunishi's unfinished words.
"It—It's overflowing too much!"
With that push just now, too much tea had spilled over. It had already flooded across the table's edge and was dripping down toward Tengen's pant leg.
Kuguruma Natsunishi: "Huh?"
He had been too busy acting cool.
"You idiot!" Tengen jumped up, frantically swatting at his trousers.
Kanae looked at the two men—who had been seriously discussing Breathing Techniques a moment ago and were now shouting in distress over a wet pant leg—and finally couldn't help but let out a giggle. She smiled and handed over her handkerchief, which carried a faint floral scent.
"If you break the cup, you have to pay for it," she reminded them softly.
"Boss!" Uzui called out to the shopkeeper with a wry smile while wiping his pants. "Another cup over here! Make it a sturdy one!"
"Coming right up!"
Amidst the commotion, Kuguruma Natsunishi's words were deeply etched into Tengen's mind. His gaze occasionally drifted to the broken wooden cup on the table, and the ninja's eyes gradually settled into a look of profound thought.