"AGH! It hurts! It hurts!"
Kazama Aoi was currently being subjected to flexibility training, and it felt as though her bones were being snapped inch by inch by Kanzaki Aoi's deceptively delicate hands.
Kanzaki Aoi wore a look of stern disapproval, her grip not loosening one bit. "Your body is too stiff; this simply won't do. For a swordsman, flexibility is paramount."
As she spoke, she gave another firm press.
"GYAAAH—!" Aoi let out a blood-curdling shriek. She was reasonably certain her lower back no longer belonged to her body.
Nearby, Tanjiro, Zenitsu, and Inosuke were undergoing their own versions of "Rehabilitation Training."
By the time the session ended, Aoi felt as though her soul had left her body. She slumped against the edge of the hallway like a puddle of melted jelly, lacking even the strength to twitch a finger.
"Aoi-chan, are you alright?" Tanjiro trotted over, handing her a towel and a cup of water with a face full of concern. "You look incredibly pale."
Aoi took the cup with a trembling hand, barely finding the energy to whisper a thank you. She looked at Tanjiro; despite being drenched in sweat, his breathing was steady and his eyes remained bright.
How is the gap between humans this massive?
[Ding! Mission Issued: Complete training alongside Tanjiro Kamado.][Reward: 500 Points, Wood Breathing, Third Form: Blade of Withered Judgment.](Description: The blade carries the lethal silence of blighted wood and the piercing vigor of new branches. A single swing delivers two distinct strikes—the first uses the resilience of withered wood to shatter the demon's bones, and the second uses the sharpness of new growth to cleave through flesh. The overlapping damage is specifically designed to bypass demonic regeneration.)[Failure Penalty: None.]
Aoi's spirit trembled as she roared inwardly: System! You're finally acting like a human! This reward is amazing! And the penalty is... nothing?! Have you been possessed by a saint?!
It felt too good to be true.
"Aoi-chan? What's wrong?" Tanjiro asked, reaching out to check her forehead for a fever.
"N-nothing!" Aoi snapped back to reality, pushing his hand away. Her cheeks were flushed red with sheer excitement.
She looked at Tanjiro, and her gaze shifted instantly. This wasn't just a teammate anymore—this was her "Golden Thigh," her one-way ticket to becoming an absolute powerhouse!
"Tanjiro!" Aoi grabbed his shoulders, shaking him with newfound fervor. "Starting tomorrow morning... no, starting now! Every single training session you do, I'm doing it with you!"
Tanjiro was startled by this sudden burst of passion. Shaken nearly dizzy, he managed to stammer, "S-sure! But... aren't you exhausted right now?"
"Tired? Me? Not a bit!" Aoi stood up abruptly, slapping her chest with confidence.
For the next two weeks, Aoi practically carved the word "overachiever" into her forehead. Although her muscles screamed in agony, her body was becoming noticeably sturdier and her movements more agile.
One evening, while she and Tanjiro were sitting on the roof to meditate, Aoi sensed someone approaching.
"You're working quite hard."
A soft, familiar voice drifted from behind them. Both Aoi and Tanjiro jumped in surprise, spinning around to see Shinobu Kocho.
She stood quietly at the edge of the roof, the moonlight illuminating her butterfly-wing haori and making her look almost ethereal. Her face wore its usual sweet smile, but the depths of her purple eyes remained an unreadable void.
"Kocho-san, why did you bring us here?" Tanjiro couldn't help but ask.
Shinobu didn't answer immediately. She walked slowly to the center of the rooftop clearing, her gaze drifting over the training dummies with a hint of nostalgia.
"This is where my sister and I used to train," she said softly, her voice carrying a trace of rare tenderness. "I wanted to entrust my dream to you—the dream of a world where humans and demons can live in peace."
Tanjiro's nose twitched. A flash of confusion and worry crossed his flame-like eyes. "Kocho-san... are you angry? Even though you're smiling, I can smell a scent of anger coming from you."
The air instantly froze.
Aoi stared at Tanjiro in horror, wishing she could reach out and sew his mouth shut. Bro! What is wrong with you? Can't you see the lady is smiling like a flower? Telling her she's angry right now is like playing with matches in a fireworks factory—you're asking for a death sentence!
However, to Aoi's utter shock, Shinobu actually admitted it.
"Is that so? Perhaps I have been angry all along. Ever since my beloved sister was slaughtered by a demon... Every time I see someone crying over a life stolen by those creatures, every time I hear a scream of despair, the rage within me continues to accumulate."
Her voice was thin, like a breeze, but every word felt like a heavy stone dropping into their hearts.
"Every day, I pray that the demons will simply vanish from this world. Every day, I wear this smile, because I'm afraid that if I stop smiling, I will be consumed by this endless cycle of fury and hatred."
Shinobu slowly raised her hand, looking at her slender, pale fingers with a self-mocking smile. Her body trembled slightly; the suppressed rage that had been tearing at her for so long was finally, unreservedly, leaking out.
"My sister said that one day she wanted to see humans and demons living in harmony. I used to hold onto that hope as well, but then I felt... that my sister's death, and the deaths of all those people killed by demons... they were all becoming a joke!"
Tanjiro simply watched her, speaking each word with deliberate weight. "I haven't experienced your pain, so I cannot judge whether your anger is right or wrong. And I cannot guarantee that your dream will definitely come true."
"However, Kocho-san," Tanjiro's eyes became incredibly clear, "it's precisely because there are people like you—people who have wept and despaired because of demons—that we cannot give up on this dream."
"I don't want to see anyone else trapped by hatred, unable to smile a real smile again, just like you."
"I don't want to see anyone else like your sister, torn away ruthlessly because of their kindness and trust."
"This dream isn't about forgiving the demons who commit evil." Tanjiro's voice wasn't loud, but it felt like a beam of light cutting through the darkness of her hatred. "It's about creating a world... where your kind of sadness and your sister's kind of tragedy never happen again."
"A world... where your smile can finally become genuine once more."
The silence returned, heavy and profound.
Shinobu was stunned. She stared at the boy—years younger than her—as if seeing him for the first time. He hadn't dismissed her hatred; he had understood her grief. He hadn't evaded her questioning; he had turned her pain into the foundation of his own resolve.
Under the warmth of Tanjiro's steady gaze, the frantic, flickering fire in her purple eyes slowly began to calm.
After a long, long time, she raised her sleeve to dab at the corner of her eyes. When she turned back, the sweet, gentle smile was back in place.
"Well," she patted her cheeks, her tone returning to its usual lightness. "Think of today as a temporary lapse in composure. You two aren't allowed to tell anyone, alright?"
She walked over to Aoi and ruffled her hair, her touch as gentle as always. "I scared you, didn't I?"
Aoi nodded stiffly, her soul having only recently returned to her body.
"Go back and get some sleep. Tomorrow... the training will be even harder." For the first time, there was a flicker of genuine warmth in Shinobu's smile.
With that, she turned and vanished into the night, leaving Tanjiro and Aoi standing on the roof in the quiet moonlight.