Tomioka Giyu arrived at the Rengoku residence half an hour earlier than scheduled.
When he slid open the wooden door, the courtyard looked completely different from last time—no empty sake bottles scattered around, the stone tiles of the training ground had been thoroughly cleaned, and several new wooden swords leaned neatly against the wall. The sharp smell of alcohol was gone, replaced by a faint scent of grass and wood.
"Tomioka-san! You're here!"
Rengoku Kyojuro's voice came from the training ground. He was dressed in training clothes, gripping a wooden sword, sweat glistening on his forehead—clearly, he had been practicing for a while.
When he saw Giyu, he immediately set down his sword and ran over, with Senjuro following behind, holding a water jug.
"Father's already waiting for you. He got up early to clean the training ground himself."
Kyojuro's voice was full of excitement, his eyes burning bright like flames.
"He said he's going to properly teach you Flame Breathing today!"
Giyu nodded, glancing around the training field. The ground was marked with fresh sword gouges—deep and steady—each one showing careful, consistent effort. It was clear that Shinjuro had been practicing again.
It seemed that their last talk and sparring match had truly reignited the former Flame Hashira's spirit.
"Come in."
The door to the study slid open, and Rengoku Shinjuro stepped out.
He wore a black training outfit, his hair neatly tied back, his face clean-shaven.
Though faint traces of fatigue lingered beneath his eyes, the decadence from before was gone. His gaze was sharp again—steady, fierce, and alive. The commanding presence of the Flame Hashira had returned.
"Tomioka Giyu."
Shinjuro walked up to him, bowed slightly, and said sincerely,
"Last time, I was drunk and behaved disgracefully. I said a lot of foolish things and even raised my hand against you. I owe you an apology."
Giyu froze, surprised that the former Hashira would apologize first.
He shook his head quickly, awkwardly replying, "It's fine."
"Circumstances aren't an excuse."
Shinjuro straightened, his tone solemn.
"As a former Hashira and a member of the Rengoku family, I should never have lost control over my emotions."
He paused, then continued,
"I won't return to the Demon Slayer Corps as a Hashira. After losing my wife, I wasted too much time. I'm no longer worthy of that title."
Kyojuro stiffened slightly but then stood taller, resolve flickering in his eyes.
He knew his father's decision was final—and that it was now his turn to inherit that flame.
When Shinjuro's gaze fell on his son, his expression softened, warm with pride.
"But I will remain a swordsman and continue to practice Flame Breathing. I have faith in Kyojuro."
His voice rose, filled with fiery conviction.
"You will pass the Final Selection soon and become the new Flame Hashira. Your talent and heart surpass mine. You'll become a flame brighter than I ever was."
"Father!"
Kyojuro's eyes glistened, his voice trembling with emotion.
"I will! I'll become the strongest Flame Hashira and protect everyone! I won't let you or Mother down!"
Senjuro stood quietly at their side, a soft smile tugging at his lips as he watched the two of them.
Giyu observed the scene, a faint warmth blooming in his chest.
He knew then—the Rengoku flame would burn brightly once more through Kyojuro.
"Enough talk," Shinjuro said, clapping Kyojuro on the shoulder before turning to Giyu.
"Let's head to the training field. I'll teach you Flame Breathing."
On the training ground, Shinjuro picked up a wooden sword and took the opening stance for Flame Breathing.
His movements were steady and powerful, his muscles taut beneath his sleeves. Every posture carried the weight of countless hours of disciplined training.
"The core of Flame Breathing," Shinjuro said in his firm, booming voice, "is to burn yourself completely."
"Unlike Water Breathing's softness or Wind Breathing's sharpness, Flame Breathing demands intensity—fierceness."
"Your breathing must be fast and forceful. Let your breath blaze inside you like fire, and then let that flame burst through your sword. Each strike should carry the resolve to burn everything away."
He took a deep breath, his chest rising and falling sharply, then swung his sword in one swift motion.
"Flame Breathing, First Form: Unknowing Fire!"
The wooden sword sliced through the air with a faint crack, a soft orange glow flickering along the blade. Though there were no real flames, the heat of his spirit was palpable.
The gust from his swing scraped across the stone tiles, leaving a shallow mark.
"Did you see that? Keep your breathing fast. Inhale deeply, exhale fiercely. Make your breath and movement one—like a flame that burns to the end, leaving nothing behind."
Shinjuro lowered his weapon and handed Giyu another wooden sword.
"Your turn."
Giyu accepted the sword, recalling Shinjuro's posture and rhythm. He took a deep breath.
But as he moved, his body instinctively followed the rhythm of Water Breathing—gentle and flowing—completely at odds with the ferocity of Flame Breathing.
"No!"
Shinjuro's voice cut through the air sharply.
"Don't use the rhythm of Water Breathing! Flame Breathing doesn't need gentleness—it demands force! Throw away your hesitation! Imagine your body as fuel, each breath igniting you from within!"
Giyu nodded and steadied himself again.
This time, he deliberately quickened his breathing, making it sharp and powerful.
In his mind, he recalled the sensation of Hinokami Kagura—the Sun's burning rhythm.
Its heat and radiance weren't so different from the intensity of Flame Breathing.
He took a deep breath, his chest rising and falling rapidly, arm muscles tensing as he swung hard. "Flame Breathing, First Form: Unknowing Fire!"
The wooden blade sliced through the air—though no orange glow appeared, the heat and force behind it were stronger than before. The strike carried more weight, and though his movements were still slightly stiff, the shape of Flame Breathing had already begun to take form.
Shinjuro's eyes lit up. "Not bad! Faster than I expected! Do it again—this time, merge in the feeling of Sun Breathing!"
"Sun Breathing?" Giyu hesitated for a moment.
"That's right."
Shinjuro explained, his tone calm but firm.
"All Breathing Styles originate from Sun Breathing, and Flame Breathing is no exception. The core of Sun Breathing is the 'sun'; the core of Flame Breathing is 'fire.' They're connected by nature. Since you've already mastered Sun Breathing, you've grasped the very root of all styles. Learning any other Breathing becomes easier from there."
Realization dawned on Giyu.
He remembered how quickly he'd adapted when learning Wind Breathing, and now Flame Breathing was proving the same. So it was because of that shared foundation in Sun Breathing.
Once again, he inhaled deeply. This time, he didn't try to separate Sun Breathing from Flame Breathing.
Instead, he let the Sun Breathing energy flow freely within him, blending it with Flame Breathing's principle of "burning oneself completely."
"Flame Breathing, First Form: Unknowing Fire!"
This time, as his wooden blade cut through the air, a faint orange glow shimmered along the edge. The gust it produced carried a tangible wave of heat, striking the stone tiles and leaving a deeper mark than before.
His movements were smoother now, no longer stiff or hesitant.
"Good!"
Shinjuro couldn't help but exclaim.
"That's it! Use Sun Breathing as your foundation, then add the essence of Flame Breathing. That's the fastest way to truly grasp its core!"
He lifted his wooden sword and took a battle stance. "Come. Let's spar. You'll use Flame Breathing, and I'll use Flame Breathing too. I'll correct your movements and rhythm."
"Yes!"
Giyu gripped his sword and took his stance.
"Flame Breathing, Second Form: Rising Scorching Sun!"
Shinjuro attacked first. His wooden blade, carried by a burst of fiery pressure, came straight for Giyu's shoulder.
Giyu inhaled sharply, shifting his Sun Breathing into the burning rhythm of Flame Breathing, syncing his movements. "Flame Breathing, Second Form: Rising Scorching Sun!"
Their wooden blades clashed with a sharp crack, intertwining streaks of orange-red light. The training ground filled with a suffocating wave of heat.
Shinjuro's strikes were precise and powerful, every blow carrying the weight of a former Hashira's strength, though he held back enough not to injure Giyu.
He corrected Giyu as they fought. "Breathe faster! Keep your arm tense! Flame Breathing isn't about holding back—drive straight through!"
Giyu listened carefully, adjusting his breathing and movement in rhythm with each strike.
He could feel it—Flame Breathing was sinking into his body, his mind, his very rhythm.
Thanks to the foundation of Sun Breathing, he could follow Shinjuro's tempo easily. In fact, during several exchanges, he even managed to counterattack.
After half an hour, the two finally stopped.
Sweat rolled down Giyu's temples, his chest heaving, arms heavy with fatigue—but inside, he felt charged with energy.
The lingering heat of Flame Breathing pulsed in his veins, filling him with a fierce, fighting spirit.
"Impressive progress," Shinjuro said, handing him a jug of water, genuine praise in his tone.
"At your pace, within half a month, you'll have fully mastered the basic forms of Flame Breathing. After that, try merging it with Water and Wind Breathing. You might create something even stronger."
Giyu accepted the jug, took a long drink, and nodded, excitement flickering in his eyes.
Learning Flame Breathing would make up for his lack of explosive power. If he could fuse three Breathing Styles—with Sun Breathing as the core—his strength would reach a whole new level.
Then, no matter whether it was facing Douma or some even stronger demon in the future, he'd have the power to protect the people he wanted to protect.
"Thank you," Giyu said sincerely.
"No need to thank me."
Shinjuro smiled faintly and patted his shoulder.
"You're a good man, and one worth trusting. When Kyojuro becomes the next Flame Hashira, I'll be counting on you to look after him."
"Father!"
Kyojuro protested immediately, his voice burning with energy. "I can look after myself! Besides, Tomioka-san is my senior—I should be the one helping him!"
Giyu glanced at the passionate red-haired youth, then at the once-broken man who now stood tall again. A rare, small smile tugged at his lips.
Sunlight spilled across the training ground, where faint traces of orange-red light still hung in the air.
Giyu gripped his wooden sword tighter, eyes filled with resolve.
His path toward strength was far from over.