Demon in Karasuno
The Doll with the Jagged Smile
The atmosphere in the Karasuno gym didn't just change when Mariam Kageyama walked in; it curdled. It was like someone had replaced the oxygen with something heavier, something that tasted faintly of iron and expensive, bitter coffee.
Mariam sat on the equipment bench, swinging her legs. Even though her feet barely reached the floor, she looked down at everyone else. Her long, dark chestnut hair was gathered into a high, sharp ponytail that looked like it could be used as a whip. Her violet eyes, dark as a bruised plum, flicked from player to player, dissecting them.
"So this is it?" she asked, her voice carrying a melodic, mocking lilt. "My brother told me Karasuno was a 'powerhouse' once. Looking at you lot, I’m guessing the power went out a long time ago."
"Hey! Watch it, kid!" Tanaka barked, though he was blushing furiously. "We’re the ones who made it to the Top 8 in the prefectural qualifiers!"
Mariam tilted her head, her bangs shifting to reveal a sliver of her forehead. "Top 8? In a backwater prefecture like Miyagi? How adorable. In London, the girls I played with would have eaten you for breakfast and used your sneakers as toothpicks."
Tobio Kageyama stood a few feet away, looking like he wanted to crawl into a hole. "Mariam, shut up. You haven't even touched a ball yet."
"Oh, don't be like that, Tobio-chan," she cooed, the suffix dripping with sarcasm. "I’m just observing the local wildlife."
She stood up, her movement fluid and eerily silent. She walked toward Hinata, who was staring at her with wide, sparkling eyes. To Hinata, she wasn't just Kageyama’s sister; she was a mystery, a small, fierce storm contained in a tiny frame.
"You," she said, stopping right in front of him. She was actually shorter than him, a feat Hinata hadn't thought possible for an upperclassman. "You’re the one who jumps, right? The little decoy?"
"I’m Hinata Shoyo! And I’m going to be the Ace!" he declared, puffing out his chest.
Mariam leaned in close, so close that Hinata could see the tiny gold flecks in her violet irises. She reached out and pinched his cheek, twisting it just hard enough to make him wince. "You’re like a little sun, aren't you? So bright it’s annoying. I think I’ll call you Sun-chan. It suits you. You look like you’d melt if I poured a little cold water on you."
"I won't melt!" Hinata squeaked, his face turning the color of his hair.
"We’ll see," she whispered, a dangerous, jagged smirk stretching across her lips.
Coach Ukai cleared his throat, trying to regain the team’s attention. "Alright, enough talk. We need to see how Mariam integrates with the rotation. Since she’s a Wing Spiker, we’re going to run a 6-on-6 scrimmage. Mariam, you’re on the B-side with Sugawara, Tanaka, and Ennoshita. Tobio, you’re on the A-side. Let’s see what the 'Demon' can actually do."
Mariam’s eyes flashed at the mention of her nickname. She didn't say a word as she stripped off her black leather jacket, revealing a sleeveless jersey that showed off the lean, whip-like muscles of her arms. Her skin was pale, almost porcelain, but it was marred by old scars on her elbows and knees—souvenirs from a style of play that clearly didn't prioritize self-preservation.
The game started, and the mood shifted instantly.
When the ball was in play, Mariam stopped talking. The mockery vanished, replaced by a cold, terrifying focus. She didn't just run; she stalked the court. Her footsteps were silent, her positioning perfect.
Sugawara, acting as her setter, sent a high ball toward the left pin.
"Mariam!" he called out.
She took off. Her approach was explosive, her small stature belying the sheer power in her legs. She didn't just jump; she soared, her body arching back like a bow string being pulled to its breaking point. For a second, she seemed to hang in the air, defying gravity.
Tsukishima and Kageyama rose to block her. It was a solid wall of hands.
Mariam didn't flinch. In mid-air, her eyes narrowed, and she did something insane. Instead of a standard spike, she twisted her wrist at a sharp, unnatural angle, snapping the ball downward with a violent *crack*. The ball didn't go over the block; it went *through* the narrow gap between Tsukishima’s arms, slamming into the floor so hard it bounced nearly to the ceiling.
The gym went silent.
Mariam landed lightly, her knees bending deep. She didn't celebrate. She just looked at Tsukishima and let out a dry, mocking chuckle.
"Is that the best you can do, Four-eyes? I could have sent that ball through your skull if I’d really tried. Move your hands faster next time, or you might actually get hurt."
"You’re a real piece of work, aren't you?" Tsukishima muttered, though his hands were slightly trembling from the wind of the ball.
"I’m a winner," she corrected him, her violet eyes glowing with a predatory light. "There’s a difference."
As the scrimmage continued, the Karasuno players realized that Kageyama’s warning hadn't been an exaggeration. Mariam played with a reckless, almost suicidal intensity. She didn't care about the floor; she would dive for balls that were already out of reach, her body skidding across the hardwood with a sickening friction burn.
At one point, she chased a shanked pass toward the benches. Instead of stopping, she launched herself over a row of water bottles, collided with a chair, and managed to pop the ball back into the air with one hand before crashing into the metal frame.
"Mariam!" Tobio shouted, stepping toward the net.
She stood up slowly, wiping a smear of blood from her lip where she’d bitten it during the fall. She looked at the blood on her fingers, her smirk widening into something truly feral. She licked the red drop away, her eyes fixed on the opposing side.
"Keep playing, Tobio," she hissed. "I’m just getting warmed up."
"She’s crazy," Nishinoya whispered from the sidelines, his eyes wide with a mix of fear and admiration. "She’s even more of a wild card than Hinata."
But it wasn't just her recklessness. It was the way she looked at the opponents. Whenever she spiked, she didn't aim for the open court. She aimed for the players. She aimed for their chests, their shoulders, their faces. It wasn't that she was trying to score; she was trying to break their spirit. She wanted to see them flinch. She wanted to see the fear in their eyes.
Every time she forced a "fumble" or a "missed dig" by sheer intimidation, she would let out that sharp, melodic laugh.
"What’s the matter, Sun-chan?" she teased as Hinata failed to receive one of her vicious, curving serves. The ball had clipped his shoulder, leaving a red welt. "Are you getting tired? I thought the sun was supposed to stay up all day."
Hinata gritted his teeth, his determination flaring. "I’m not tired! Give me another one!"
Mariam’s expression softened for a fraction of a second—a flicker of genuine interest—before the mask of the Demon slid back into place. "Careful what you wish for, little bird. I might just clip those wings."
By the time the scrimmage ended, Mariam’s side had won, but the victory felt heavy. The team gathered around the water bottles, everyone breathing hard. Mariam was a mess of scrapes and bruises. Her knees were raw and bleeding, and a dark bruise was already forming on her hip.
Takeda-sensei hurried over with a first-aid kit. "Mariam-san, you need to be more careful! You can't play like this every day, you’ll destroy your body!"
Mariam took a bandage from him and applied it to her knee with practiced indifference. "Pain is a great teacher, Sensei. It reminds me that I’m still alive. Besides, if the other team is too scared to touch the ball because they’re afraid of getting hit, then I’ve already won the war before it’s even started."
"Volleyball isn't a war," Daichi said firmly, stepping forward. "It’s a sport. We play together. We support each other."
Mariam looked up at the captain, her violet eyes cold. "Maybe for you. But where I come from, if you aren't the predator, you’re the prey. I didn't come back to Japan to make friends, Captain. I came back to win. If you can't handle my style, then maybe Karasuno isn't as tough as Tobio said."
She stood up, ignoring the sting in her legs, and walked over to Hinata. He was sitting on the floor, rubbing his sore shoulder. She reached out and tilted his chin up with her finger.
"You’ve got guts, Sun-chan," she murmured. "Most people start crying after the third serve. You just keep coming back for more. It’s almost... endearing."
"I want to win too," Hinata said, his voice steady despite the intensity of her gaze. "And I want to see your best plays! Not just the scary ones, but the ones that make you happy!"
Mariam froze. The word 'happy' seemed to strike a chord she wasn't prepared for. Her smirk faltered for a heartbeat, her violet eyes widening. She quickly recovered, flicking his forehead and stepping back.
"Don't get ahead of yourself," she snapped, though the bite in her voice was gone. "I don't play for 'happiness.' I play for the kill."
She turned and headed for the equipment room to grab her bag. Tobio followed her, his expression grim.
"Mariam," he said, catching her by the shoulder. "You need to dial it back. This isn't London. You don't have to carry the weight of everything on your own. You have a team now."
She shoved his hand off, her back to him. "A team? You mean a bunch of kids playing house? They don't know what it’s like, Tobio. They don't know what happens when you lose everything because you weren't 'scary' enough."
"Is that what happened over there?" Tobio asked quietly. "The 'Demon' nickname... you didn't just earn it. You chose it, didn't you? To hide behind."
Mariam stiffened. She turned around, her face a mask of cold fury, but her hands were clenched so tightly her knuckles were white. "Watch your mouth, little brother. Just because you’ve found a place where you fit in doesn't mean I have. I play the only way I know how. And if it breaks me, then I’ll die on the court. At least then I’ll be useful."
She didn't wait for a response. She grabbed her leather jacket and walked out of the gym, the heavy doors slamming shut behind her.
The team stood in silence for a long time. The sunset outside cast long, blood-red shadows across the floor, highlighting the spots where Mariam had left her mark.
"She’s... she’s hurting," Sugawara said softly, looking at the door. "That kind of aggression doesn't come from nowhere. She’s playing like she’s trying to punish herself as much as the opponents."
"She’s a Kageyama," Tanaka added, rubbing the back of his neck. "They’re all a bit intense, but she’s on a whole different level. It’s like she’s a beautiful doll that’s been put back together with jagged glass."
Hinata looked down at his shoulder, where the red mark of her ball was still stinging. He didn't feel angry. He felt a strange, deep ache in his chest. He remembered the way her eyes had flickered when he mentioned being happy.
"I’m going to make her smile," Hinata said suddenly, his voice loud in the quiet gym.
"What?" Kageyama blinked.
"A real smile!" Hinata shouted, pumping his fists. "Not that scary, sharp one! A real one! I’m going to show her that volleyball is fun, and she doesn't have to be a demon to win!"
Kageyama looked at his teammate, then at the closed doors. He knew his sister better than anyone. He knew the darkness she had faced in the professional circuits of Europe—the pressure, the isolation, the betrayal that had turned her heart into a fortress.
"Good luck with that, Hinata," Kageyama muttered, though a small part of him felt a spark of hope. "She’s more likely to bite your head off than smile at you."
"Then I’ll just have to be the brightest sun she’s ever seen!" Hinata declared.
Outside, leaning against the brick wall of the gymnasium, Mariam Kageyama let out a long, shaky breath. She pulled her jacket tighter around her, her fingers brushing the fresh bandages on her knees.
She looked up at the darkening sky, the first stars beginning to twinkle. For the first time in years, her pulse wasn't racing with anger. It was racing with something else. Something terrifying.
"Sun-chan," she whispered to the empty air, the name tasting strange on her tongue. "You’re going to be the death of me."
She began to walk, her limp barely noticeable, her silhouette disappearing into the shadows of Miyagi. The Demon had arrived at Karasuno, and though she intended to burn everything down, she had no idea that she was walking straight into a fire that might actually keep her warm.
The experiment had begun, and for the crows of Karasuno, the game had never been more dangerous—or more desperate. As the lights of the gym finally flickered out, the echo of Mariam’s jagged laugh seemed to linger in the rafters, a promise of the storms yet to come.