Two months passed in the blink of an eye. Tatsuya didn't slack off after mastering the forms. He refined every strike, seeking the pinnacle of speed and control.
The best way to improve was through combat. This meant the last two months were exhausting for Kuwajima. Tatsuya hounded him for duels from dawn till dusk. The clearing echoed with the sound of clashing blades and Tatsuya's stubborn shouts: "Again, old man! I'll dodge it this time!"
The night before the Final Selection, Tatsuya visited his master's room.
"Tomorrow you depart," Kuwajima said solemnly. "You must know the ranks. From lowest to highest: Mizunoto, Mizunoe, Kanoto, Kanoe, Tsuchinoto, Tsuchinoe, Hinoto, Hinoe, Kinoto, Kinoe. Above Kinoe are the Hashira."
He stared at Tatsuya with expectation. "With your talent, do not linger in the lower ranks. Make me proud and become a Hashira as quickly as possible! Let the name of the 'Roaring Hashira' echo through the Corps once more!"
Tatsuya grinned with confidence. "Don't worry, Master! Your disciple is fast and hits hard! A Hashira rank? I'll have it in no time. Maybe next time I come back, you'll have to call me 'Lord Hashira'."
"You brat! Watch your mouth!" Kuwajima made a move to strike him, but he couldn't hide his smile.
The mood then turned serious. Tatsuya shared his observations about Kaigaku—his effort, but also the persistent wall between them. Kuwajima listened, then dropped a topic that made the air turn cold.
"Tatsuya... do you know that there are 'Demons who can use Breathing Styles'?"
"What?!" Tatsuya's pupils shrank. "Breathing is for us Slayers to fight demons! How could a demon... that shouldn't be possible!"
"Nothing is impossible," Kuwajima said raspy, his voice etched with the pain of years past. "You've asked several times why I lost this leg, haven't you?"
He pointed to his prosthetic left leg. "I owe this to a demon who could use a Breathing Style."
Tatsuya held his breath.
"It was a top-level subjugation mission. I led a team of five. The others were all experienced, powerful Kinoe-ranked slayers." Kuwajima's eyes turned hollow. "In a single encounter... just one... my four comrades were killed instantly. I was the only one who survived, only because they died protecting me. I crawled away with a shattered leg and heavy wounds."
The room fell into a dead silence. "And that... was just the demon acting on a whim. It only used one strike."
"Master, what kind of demon was it? What Breathing did it use?" Tatsuya's voice was dry. "Did the Corps kill it?"
"The Corps sent four Hashira to hunt it... but the demon had vanished," Kuwajima shook his head. "Its name and the Breathing it used—I will not tell you now."
He cut off Tatsuya's questions with a gaze as sharp as a blade. "On the day you become a Hashira, I will tell you everything. Knowing now would only fill you with useless hatred and fear, disturbing your growth. Do you understand?"
Tatsuya looked into his master's eyes and knew there was no point in pushing. He nodded heavily. "I understand, Master."
"As long as I walk the path of a Demon Slayer, the day will come when I encounter that thing. And when I do, I will take its head!"
As the night talk drew to a close, the gravity on Kuwajima's face softened slightly. He turned to a cabinet and carefully took out a neatly folded haori, handing it to Tatsuya.
"This is...?"
The haori was a deep, dignified black. The fabric was thick and high-quality, its edges embroidered with simple, flowing gold threads representing lightning. Under the flickering lamplight, it shimmered—solemn yet carrying the sharp edge unique to Thunder Breathing.
"Take it. I know you're a vain brat who likes your 'colorful' blacks. I couldn't get you 'colorful,' but I had this specially made for you. If you wear it out or tear it, find someone else to fix it. I don't do that feminine needlework."
Likely uncomfortable with such a sentimental scene, the old man's tone remained stiff and awkward, but Tatsuya could feel the deep care and blessing hidden within the words.
"Thank you, Master!" Tatsuya took the garment. It felt sturdy yet comfortable. He could already imagine himself looking dashing while wielding his blade in this. "Hehe, clothes really do make the man! I definitely look more like a future 'Thunder Hashira' now!"
"Thunder your head! It's Roaring Hashira! A 'Thunder Pillar' is a utility pole! If you want to be a utility pole so bad, go stand outside and guard the mountain all night!"
"Hahaha! My mistake, Master! I'll get out of your hair now!"
With a heart full of both weight and warmth, Tatsuya left his master's room. Kuwajima sat alone under the lamp, listening to his disciple's retreating footsteps. After a long silence, he let out a faint, worried sigh.
Kaigaku... I know your nature... but that is exactly why I cannot give up on you. Tatsuya, I told you those things because I wanted you to understand... I still choose to teach Kaigaku. This is a gamble of faith and responsibility. But... if I fail, the worst outcome is that your junior becomes the next... Breathing Demon.
As Tatsuya walked down the hallway to pack, his mind was racing. A demon using a Breathing Style? How is that possible... unless... A chilling thought struck him like black lightning, making him stop in his tracks. Unless that demon was once a Slayer! A swordsman who trained in Breathing, betrayed humanity, and turned to the side of demons?!
His master was using a cruel, indirect way to warn him: betrayal was not without precedent in the Corps. And for someone with talent but a corrupt heart, the destruction they could cause with a Breathing Style would be catastrophic. He thought of Kaigaku's deep-seated selfishness hidden under his submissive mask. A shadow of worry for his master—and his junior—loomed over him.
He gripped the new haori tight, looking out at the starless night sky. The path he was about to step onto tomorrow felt even heavier now.
"Junior Kaigaku... even if I'm not on the mountain... I'll be watching you!"