Tomioka Giyu was sitting in the courtyard watching Tomioka Tō practice Water Breathing when he opened the letter sent from the Butterfly Mansion.
The paper carried a faint floral scent—the kind Kocho Shinobu always used. Her handwriting was neat and delicate, yet every stroke carried a quiet determination.
"Tomioka-san, I hope this letter finds you well. Kanao has been making great progress lately. She can now handle the basic forms of Flower Breathing with ease, though she still hesitates to draw her blade. Nee-san is guiding her slowly."
"Also, about the concept you mentioned last time—'using skill to make up for strength'—I tried adjusting my movements during training, and it really helped conserve energy. But my strength is still too little. Even if I strike at a demon's joints, I still can't sever the neck in one blow…"
"P.S. The Butterfly Mansion has developed a new batch of hemostatic medicine—it works much better than the previous version. I've sent you some via crow for use during missions."
Giyu's gaze lingered on the words 'too little strength.' His fingertips brushed lightly across the paper.
He remembered her past life.
How Kocho Shinobu had used her own body as poison to kill Douma in a near mutual death.
She had taken that path because of her lack of physical strength.
He picked up his brush and wrote carefully, the strokes straight but slightly stiff:
"If strength is lacking, use other means to make up for it. I have seen someone combine poison with swordsmanship—coating their blade with venom. Even without decapitation, the demon becomes paralyzed. You may try experimenting. If needed, I can supply demon toxin samples."
When he finished, he folded the letter, placed it into a bamboo tube, and handed it to the waiting crow outside the window.
The crow took the message in its beak and flapped away toward the Butterfly Mansion.
Nearby, Tomioka Tō stopped his movements and wiped sweat from his forehead. "Sensei, was that a letter from Shinobu-san?"
"Mm."
Giyu nodded. "She's practicing Flower Breathing. Met some difficulties."
Tō blinked. "Shinobu-san's that strong, and she still has trouble?"
"Everyone does."
Giyu stood and approached him. "Your Water Breathing Third Form—your rhythm broke again. Try once more."
Tō immediately took position and inhaled deeply. "Water Breathing, Third Form: Flowing Dance!"
The blade cut through the air, more fluid than before, but his breathing was still rough. Each slash carried too much force—too wild, as if he was pouring all his strength into every motion.
He had been training with Giyu for three months now.
A month ago, Tō had already mastered all the basic Water Breathing forms—faster than any swordsman his age. A prodigy, one might say.
But Giyu soon noticed something off.
Tō's breathing was too violent.
Water Breathing emphasized continuous flow—gentle and precise, like water nurturing all things.
But Tō's breathing was harsh and forceful. Each slash came down like a storm wind—fierce, powerful, but lacking control.
The "flow" of Water Breathing, in his hands, had turned into a raging torrent—intense, but unstable.
"Stop."
Giyu spoke calmly. "Your breathing's too fast. Slow it down. Let it sink lower."
Tō frowned and tried again, but the moment he moved, his breath faltered once more.
Frustration filled his face. "Sensei, I can't do it… every time I hold the sword, I just want to swing harder."
Giyu studied him, and suddenly, a name came to mind—Shinazugawa Sanemi.
The fierce, tempestuous nature of Wind Breathing—Tō's movements carried that same wildness.
Perhaps… he wasn't meant for Water Breathing at all.
He might belong to Wind Breathing.
Once the thought surfaced, Giyu didn't hesitate.
He walked to the corner of the room, took another bamboo tube, and wrote quickly:
"Come to the Echigo base at once. I have a favor to ask."
The addressee: Shinazugawa Sanemi.
Two days later, the Wind Hashira appeared at the gate of the base.
Same sharp presence as always. When he saw Giyu, his voice carried irritation. "What now? This isn't about that butterfly again, is it? I'll tell you, I've already rushed over three times this month for nothing. If you're wasting my time again, I'm done."
"It's not about Kanae," Giyu said, stepping aside to let him in. He gestured toward the courtyard. "It's about him."
Sanemi followed his gaze and saw a small boy practicing sword swings. His form was awkward but fierce—each motion sharp with determination.
"That your student?"
"Yeah. Tomioka Tō."
Giyu nodded. "He can't grasp Water Breathing properly. I think Wind Breathing suits him better. I'd like you to show him the basics."
Sanemi raised a brow. "You want me to teach your disciple? What, can't you handle it?"
"Water Breathing and Wind Breathing are completely different. I don't want to mislead him," Giyu said honestly.
Sanemi stared at him for a few seconds—probably remembering their previous bet. Then he clicked his tongue. "Fine. But I've got no patience for kids. I'll only say it once. Whether he gets it or not is on him."
He strode into the courtyard.
Tō stopped swinging and looked up, tense, at the scarred man approaching him.
"Kid, watch closely."
Sanemi drew his Nichirin Sword in one smooth motion, wasting no breath on pleasantries.
"The core of Wind Breathing… is destruction."
"No matter what stands in your way, cut through it with a single strike.
Your breathing must be fast—sharp. Let the air rush into your lungs like a storm, then unleash it through your blade."
Sanemi drew a deep breath, his body leaning forward in a flash. "Wind Breathing, First Form: Dust Whirlwind Cutter!"
A blur swept across the courtyard—only a gray-black arc remained in sight. In the next instant, the wooden stake before him split cleanly in two, the cut smooth as if measured by a blade's edge.
"See that?"
Sanemi sheathed his sword. "Your breathing should flow with your movements. Don't overthink. Let your power move with the wind."
Tō's eyes widened in awe. He nodded hard, grabbed his wooden sword, and mimicked the motion.
His breathing was still uneven, but this time, there was no stiffness—only the raw, violent pulse of Wind Breathing.
His swing wasn't as fast as Sanemi's, but it carried a sharp whistle through the air, a sound that tore at the wind.
Sanemi watched him quietly, no mockery this time. "Not bad. You're not stupid after all. Remember—wind can't be chained down. Your blade should be the same. When you want to strike, strike."
With that, he turned to leave. At the doorway, he shot a glance at Giyu. "Next time you drag me here for nothing, I'll make sure you regret it."
Giyu nodded. "Understood."
After Sanemi left, Tō threw himself into training even harder.
He didn't abandon Water Breathing completely. Instead, he began trying to blend in the destruction of Wind Breathing.
Gradually, his technique began to change—
No longer gentle flowing water, but raging waves. Each strike carried the force of a storm, yet retained the smooth continuity of Water Breathing.
"Water Breathing, Third Form: Flowing Dance!"
Tō's wooden blade swept forward. The arc it drew surged like waves, bursting with the whistle of slicing air. The wooden stake before him exploded into flying splinters.
Giyu stood nearby, watching, and a realization stirred within him.
The strength of Water Breathing lay in its endurance and defense—like the Eleventh Form, Dead Calm, an impenetrable shield; or the Third Form, Flowing Dance, a fluid evasion.
But its weakness was clear—its strikes lacked destructive power. Against tough-skinned demons, it was hard to kill in one blow.
What if… he added the force of Wind Breathing to the flow of Water Breathing?
A flood.
Water, gentle on its own, could destroy everything when it turned to floodwaters—continuous like the sea, yet violent like a storm.
The thought made his pulse quicken.
Giyu stepped into the courtyard, drew his Nichirin Sword, and took a deep breath. Energy coursed through him.
He began not with Water Breathing, but the rhythm of Wind Breathing—short, fierce breaths, wind rushing through him like a tempest.
"Wind Breathing, First Form: Dust Whirlwind Cutter!"
His sword flashed, slicing through the air with a cutting whistle. It wasn't as refined as Sanemi's, but the edge was unmistakably sharp.
Then, he shifted again—his breathing changing, his presence brightening. The air around him grew warm, radiant.
"Sun Breathing, First Form: Dance!"
Golden light traced through the air, brilliant and destructive.
And then—he moved again.
He began weaving them together: the breaking of Wind, the radiance of Sun, the flow of Water.
Inside him, three currents intertwined—Wind's violence, Sun's purity, Water's endless flow. Under the guidance of Sun Breathing, they fused, becoming something entirely new.
This power carried Water's continuity, Wind's piercing force, and Sun's scorching dominance.
Giyu opened his eyes. His blade gleamed faint blue under the sunlight, faint threads of gold shimmering along the edge.
"Water Breathing… Twelfth Form…"
He whispered the name under his breath, stepping forward and swinging his sword.
The strike poured out like a tidal wave, roaring with unstoppable force.
The wooden stakes shattered to dust, the ground beneath split open, a deep groove carved through the dirt.
The sound of rushing water filled his ears—not the gentle trickle of a stream, but the thunderous crash of a flood.
Giyu sheathed his sword. His chest rose and fell sharply, every breath heavy.
That strike had drained almost all his energy—but the power behind it had far surpassed any form of Water Breathing he'd ever known.
The Twelfth Form—complete.
He looked down at his palm, still tingling from the vibration of the blow.
This form held the flow of Water, the destruction of Wind, and the purifying fire of the Sun. A single technique capable of overwhelming nearly any enemy.
"Sensei! That was amazing!"
Tō ran up, eyes wide with admiration.
Giyu glanced at him, the faintest trace of a smile touching his lips. "Keep training."
"Yes!"
The sun dipped low, its golden light spilling over the courtyard, stretching their shadows long across the ground.
Giyu stood quietly, feeling the lingering pulse of energy inside him. His resolve solidified like tempered steel.
Less than half a year remained before Kocho Kanae's tragedy.
Now, he had mastered Sun Breathing, forged a new form of Water Breathing, gained Sanemi's strength as an ally, and a disciple who was steadily growing stronger.
This time, he would protect what he could not before.
His hand tightened on the hilt of his Nichirin Sword. The wave-patterned scabbard gleamed under the fading light, like a surge of water rising to crash against the darkness ahead.