The Hidden Demon Slayer (DEMON SLAYER X OC)

Chapter 18: Echoes Beneath the Moonlight

The moon hung high, veiled by streaks of dark cloud, casting a ghostly pall over the forest clearing behind Hanabi's cottage. Nariko stood alone beneath the trees, the wind tugging at the edges of her cloak. Her katana was sheathed at her hip, but her heart beat like she was already mid-battle. Her eyes flicked toward the faint light spilling from the cottage windows, where Kenzhou and Hanabi were resting. The bond growing between the three of them felt strangely steady. Familiar. Maybe even safe. But safety wasn't why she came this far.

"I was supposed to find Master Ristuka by now..."

The name echoed in her mind like a prayer half-forgotten. The one who took her in when she was still training to become a demon slayer. The one who taught her everything she needed to know about focus, form, and control. Not just of the sword, but of herself.

Ritsuka was the first to see strength in her when others only saw volatility. Where others feared her reckless spirit, Ritsuka shaped it into precision. A tempest into a blade. She remembered those early mornings on the mountainside, swinging her blade until her arms went numb, only to hear Ritsuka's voice behind her. "Again. One more swing. One more breath. One more moment of control, Nariko."

She hadn't seen her since that day—the day they shared lunch beneath the flowering pear tree near the training grounds. Ritsuka had brewed a bitter green tea, and Nariko had brought grilled rice balls wrapped in dried plum leaves, her favorite. They talked about everything and nothing. About sword form. About thunder breathing. About what Nariko would do after the war.

"Maybe I'll retire early," Nariko had joked. "Start a little noodle stall somewhere peaceful."

"Only if I get free meals," Ritsuka said, nudging her with a dry smile.

That was the last time Nariko heard her laugh.

Ritsuka had tied Nariko's hair back herself before she left. "Stay sharp. Come back alive," she had said, as always. But that time, she hesitated. Her hand had lingered on Nariko's shoulder for just a moment longer. Her eyes looked a little too serious. Nariko had bowed. She had smiled. She never thought it would be goodbye.

But then came the mission—just outside her home village. Rumors of demons. Weak ones, they said. A simple task. What she found was Akaza. Towering. Smiling. Drenched in blood.

Her home was ash and silence. Her family lay broken before her—mother, father, older brother. All gone. She couldn't move. Couldn't scream. Could only stand there as Akaza turned to her and said the words, "I thought you'd never come. I saved a little grief for you." The pain hit her before the transformation did. And when she awoke, she was changed. She ran. Hid. Never returned to the Corps. Never saw Ritsuka again.

Nariko blinked back tears now, standing in the moonlight behind Hanabi's cottage. "You'd hate what I've become," she whispered to the wind. "But I'm still trying, Ritsuka-san. I'm still fighting."

A voice in her head whispered. "You're being selfish. Staying here means dragging Kenzhou and Hanabi into danger. But if you go, they'll have to face Muzan's wrath without you. And what if you never find her?"

She closed her eyes, fists tightening. She could still see the look in Kenzhou's eyes when he came back to himself, when he didn't kill her because Hanabi called him home. That kind of awakening was rare. It needed to be protected. "Damn it..." Nariko muttered. "Why is doing the right thing always the hardest choice?"

A twig snapped behind her. She spun, hand on her blade—but it was only Kenzhou, half-shrouded in moonlight. "You okay?" he asked quietly. She sighed and looked away. "Just thinking."

"You're wondering if you should leave." That caught her off guard. "Yeah."

"I get it," Kenzhou said. "You're being hunted, and staying means putting others at risk." Nariko met his gaze, searching for judgment. There was none. "But," he continued, "if Muzan really is coming for all of us, we stand a better chance together. You helped break his control over me, Nariko. I owe you."

She hesitated. "And what if I lead him right to your doorstep? To Hanabi?"

Kenzhou's eyes darkened. "Then we make sure he never reaches it." Nariko stared at him, then gave a bitter little smile.

"You're still kind of a dumbass."

He smirked. "You're not wrong."

She exhaled and looked back up at the sky. Maybe she'd still go looking for Ritsuka. But not yet.

The moon had drifted past its peak now, casting softer shadows through the trees. Nariko and Kenzhou stood side by side in the clearing, their breath misting faintly in the cool night air. The tension between them had shifted—no longer strained, but solid. Sharpened by mutual understanding.

Kenzhou's arms were crossed as he stared out into the darkness. "He'll send someone soon. A scout. Maybe an Upper Moon."

"Then we crush them," Nariko said without hesitation. He glanced at her, brow raised. "Confident now?"

She gave a crooked grin. "I mean, we've got a former demon assassin with a grudge, a pacifist demon with a temper, and a sweet girl who radiates enough emotional power to crack Muzan's control. Seems like a decent party."

Kenzhou huffed a quiet laugh. "Not sure I'd call that balanced."

"Well, balanced or not..." Nariko stretched her arms overhead, then looked at him with a raised eyebrow. "We do have to protect your lover after all."

Kenzhou blinked. "...What?"

Nariko smirked, savoring his reaction. "You know. Hanabi."

His eyes widened ever so slightly, and a faint red crept up his neck. "She's—she's not—Hanabi's not—" He tripped over his words like a blade missing its mark. "We were close. Before. She's important to me, yes, but—"

Nariko raised both hands, mock innocence on her face. "Hey, I'm not judging. I think it's sweet. Good for you, lovebirds." Kenzhou turned away, clearly flustered. "You're impossible."

Nariko burst out laughing. Not a quiet chuckle this time, but a genuine, unrestrained laugh that echoed into the trees. She clutched her side and leaned slightly forward, eyes glinting with mischief. "Oh my god, that look on your face!" she wheezed. "You looked like you got stabbed in the chest by a flower petal! Is that how angsty boys look when they're in love?"

Kenzhou groaned and rubbed the back of his neck, trying—and failing—to suppress the crimson rising in his face. "I don't get flustered," he mumbled.

"You just did!" she shot back, grinning wide. "You're like a walking tragedy half the time, and then I say 'your lover' and suddenly you're fifteen again." He sighed, lips twitching despite himself. "You're enjoying this far too much."

"I earned this moment," Nariko said proudly. "You almost killed me earlier, I think I deserve a little entertainment."

"Glad I could provide," he muttered dryly. She gave him a playful shove with her elbow. "Relax, Kenzhou. I'm not actually trying to humiliate you. Hanabi's lucky, that's all." His expression softened, just slightly. "No. I'm the lucky one." Nariko blinked, caught off guard. For a moment, she didn't say anything. Then...

"...Wow," she said, tilting her head. "You really are in love with her."

Kenzhou stiffened like she'd just punched him in the ribs. His face turned a deeper shade of red. "I—I never said that."

"You didn't have to!" she laughed, pointing at his face. "Look at you! You're blushing so hard it's practically glowing."

"I'm not blushing," he muttered, eyes darting away. "You're imagining things."

"It's been so long since I saw someone who's red from being in love with someone," Nariko shot back, still trying to hold her laughter.

"Great. I'm so glad my humiliation is entertaining you." Nariko just laughed again, eyes twinkling. "Don't worry. Your secret's safe with me."

Their teasing faded into comfortable silence once more, the kind that came only after shared battles and shared burdens. But beneath it, something had shifted. They weren't just surviving anymore. They were living again.

Then a cold gust swept through the trees. Kenzhou's expression darkened instantly. He turned, scanning the treeline. Nariko's laughter faded as she sensed it too. An unnatural stillness, a shift in the air. "Someone's here," she murmured as her hand went to the hilt of her sword. "And they're close."