The dorms were finally quiet.
Denki Kaminari's room was dimly lit by the string lights he'd haphazardly taped above his bed. He sat cross-legged on his bed in nothing but loose basketball shorts, hair still a little damp from the shower.
In his lap rested the thing Mei Hatsume had basically tackled him with two days ago. It happened right after the internship reports were turned in. Denki had been wandering the support course halls, half-hoping to bum some free snacks off Sato, when Hatsume burst out of her workshop like a pink-haired missile.
"Kaminari! ELECTRIC BOY! You're exactly who I needed!" She'd grabbed him by the wrist and dragged him inside before he could protest. Tools clattered, sparks flew, and somewhere in the chaos she shoved the device into his hands.
It was sleek, matte black with thin glowing orange circuits tracing elegant lines along its length. About as long as his forearm, thicker in the middle, tapering toward a rounded, slightly flared head.
A small port sat at the base, clearly designed for quirk input. It looked expensive and vaguely… suggestive.
"This," Hatsume had declared, eyes manic behind her goggles, "is the VoltRelax 3000! Prototype stage seven-point-four! It's a full-body relaxation module. You charge it with your electricity; it converts the energy into perfectly tuned vibration patterns and mild bioelectric pulses. Tension? Gone. Muscle fatigue? Obliterated. Stress? What stress?"
Denki tilted his head. "So… it's just a fancy massage tool?"
"Massage tool, deep tissue reliever, post-battle recovery miracle, call it whatever you want! The point is, your quirk is the perfect power source. Most people would burn it out in ten seconds. You? You could keep it running for hours." She'd leaned in way too close. "Hours."
He remembered laughing nervously. "Uh… cool. Thanks?"
"Test it! Give feedback! Bring me data!" Then she'd shoved him out the door with a manic cackle.
That was two days ago. Now, alone in his dorm, Denki turned the device over in his hands; the weight felt nice and solid.
He flicked the small switch on the side—nothing. Of course. It needed charging. "Alright, let's see what you've got…" he muttered.
He pressed his thumb to the port and let a gentle current flow in. The circuits lit up immediately, soft orange light pulsing in time with his heartbeat. A low, smooth hum started.
"Okay… that's kinda nice already." He exhaled, shoulders dropping. Leaning back against the pillows, he dragged the rounded head slowly across his collarbone.
The vibration was deep, almost liquid, sinking straight into muscle. He moved it lower, over his pecs, then down the center of his stomach.
The sensation was... okay? More ticklish than relaxing. Not bad, but not the mind-blowing relief Hatsume had hyped.
"Huh. Maybe I need more juice." He upped the input. A thicker stream of electricity flowed in as the hum deepened. The vibrations intensified, becoming stronger and faster. Now it actually felt decent against his body, loosening the knot from carrying boxes all day.
"There we go..."
It felt warm, kinda nice. One more notch. Just to see. He poured in a bigger surge—nothing crazy, but definitely more than before.
That's when it happened.
The circuits flared bright orange—too bright. A high-pitched whine cut through the hum, then—CRACK! A violent back surge ripped straight back into his palm like a lightning whip. Electricity didn't flow out; it rebounded, amplified, and wild.
"SHI—!!" Denki's whole body locked up, every muscle seizing at once. His teeth clacked together, eyes rolled back, and hair stood straight up as blue-white arcs danced over his skin.
It wasn't the pleasant tingle of his quirk going haywire—this was pain. Sharp, burning, like someone had jammed live wires straight into his nerves. He convulsed once, twice—arms jerking, legs kicking out—before collapsing sideways onto the bed, the device clattering to the floor still sparking weakly.
For several long seconds he just lay there twitching, breath coming in ragged gasps, tiny aftershocks popping under his skin.
"...ow."
His voice cracked, pathetic. When the room finally stopped spinning, Denki stared at the ceiling, chest heaving. "That... was not relaxing." He winced as another residual zap made his fingers curl.
****
"Fuck this trash!" Denki spat as he threw the device in before slamming the lid of the recycling bin.
He was barefoot and outside, feeling the cool night air but didn't care; the air in his room reeked with the faint stink of burnt plastic.
Irritated, he walked into the kitchen, hoping to find milk or water. The kitchen light was still on even though the building was dark.
Someone was up. Tsuyu stood at the sink, back to him at first. She wore a thin white crop top that barely reached the bottom of her ribs; the soft cotton stretched taut over the perky swell of her breasts.
Below that, snug gray boxer briefs clung to her hips and ass like a second skin, outlining every curve. It was quite impossible not to stare as it drew his eyes with ease, as her ass was noticeably rounder and plumper than her small build suggested.
Her hair hung loose and slightly tangled, a few damp strands clinging to her nape like she had just washed her face. She looked relaxed and way more distracting than she was probably meant to be.
She turned when she heard his footsteps, her big dark eyes blinking slowly as she held a glass cup. She didn't wear a bra, as her nipples poked against the fabric.
"Denki?" Her voice was quiet and sleepy. "You're up...and you look strange."
"Strange?"
"Yeah, like fucked up." She replied, taking a closer look. "Did you electrocute yourself or something?"
Denki rubbed the back of his neck, suddenly hyperaware of how shirtless he was. "Yeah...long story. I almost got killed by a tool Hastume made."
Tsuyu slightly tilted her head, her tone even despite the news. "Sounds painful. Want water or milk?" She didn't wait for an answer as she reached for a second glass.
"What am I saying? Of course you would need milk." She continued, pulling the fridge door open. Denki stayed by the counter, trying not to stare, but when she bent forward to peer deeper inside the shelves, he couldn't help himself.
She was extremely sexy with the way her ass was pushed out, the way her thighs spread just a bit for balance, and the gentle arch of her back—it all hit him at once. Tsuyu didn't even know what she was doing, and that made it worse.
Denki's dick twitched hard under his shorts, heat rushing downwards. He swallowed, trying to keep his head straight.
Fuck. Don't just watch like a creep; help her.
He put his palm flat on her back, just to let her know to stand up. Tsuyu straightened almost immediately, her hand flying to the spot he touched. She glanced back at him, eyes a little wider.
"My bad...did I hurt you or something?" Denki yanked his hand back.
She shook her head slowly, face still calm but a light flush on her neck. "No, nothing really. I almost forgot you were here." She raised her other hand up, indicating the carton of milk. "I was just so focused on taking this when you touched me; I almost thought it was a ghost."
'That's weird.' Denki thought as he nodded, watching her pour milk into the glass cups. 'Or she's just not comfortable; I'll try my best to not touch her.'
He collected his cup from her, his finger slightly brushing against her as he chugged the cold milk. He lowered the cup and saw her staring at him.
He wiped his lip with his palm. "What? Milk on my face?"
Tsuyu held his gaze for a second, then spoke, her voice calm.
"Denki, touch me again."
Denki froze, glass halfway to his mouth. The kitchen was quiet except for the fridge humming.
"W-what? Touch you... again?" He repeated, voice cracking just a bit at the end. He set the glass down on the counter before he dropped it. "Like...where?"
"Don't misunderstand me. I felt something when you touched me." Tsuyu slightly pressed her lower back, like she was trying to hold onto the feeling. "You don't need to think about it; just touch me. I just want to confirm."
Denki's brain short-circuited for a second but not in the usual way after an overload. This was different, and Tsuyu's calm stare wasn't really helping matters.
He stepped closer, the space between them shrinking to nothing. His dick was throbbing fully against his shorts; he just hoped she wouldn't look down. He held her palm and stared awkwardly, despite his raging boner. He didn't feel anything special, except for her soft palm and slender fingers.
Tsuyu let out a small, quiet breath as her eyes fluttered halfway shut. "Wow, how are you doing this?" She muttered.
"Doing what?" He arched an eyebrow.
"You should stop joking with me, Denki." She replied as she leaned towards him, her body now resting on him. He froze as he felt her nipples turning hard as they poked his chest.
"I need more," she continued, wrapping her arms around his waist as her breath grew shallower.
Denki closed his eyes, a quiet prayer in his mind. She was pressed against him, and his dick was hard. Yup, she would notice and call him a freak.
Right?
He opened his eyes and noticed she was still pressed on him. She could feel his dick against her body, but she didn't say anything. Did she like it? The thought quickly vanished as he looked down over her shoulder, her round ass getting his attention.
Don't you grab her ass; don't grab it! Be chill. Don't be a perv.
His hands hovered for a second, settling on her waist. He tried his best to keep it tame, even though every nerve was screaming to grab handfuls of that ass.
Tsuyu suddenly tilted her head up, startling him as her big dark orbs locked on his. He wanted to go speak but was cut off immediately as she pushed up on her toes and kissed him. Not a peck but a deep, open-mouthed tongue sliding right in.
Denki's eyes went wide with shock. 'What the fuck is happening right now?' He thought, but his body moved on autopilot. He groaned into her mouth, leaning down hard on her. Their kiss was hungry and messy.
One hand stayed on her waist. The other… he couldn't stop it. It dropped lower, sliding down her back, then finally cupping one full cheek of her ass. Firm, round, and way softer than it looked. He squeezed harder than he meant to, pulling her tighter against his aching dick.
Tsuyu moaned quietly into the kiss, leaning more into him. She broke the kiss just enough to breathe, lips brushing his.
"More," she whispered, voice still calm but thick with want. "Touch me more."
Denki's head was spinning, horny fog everywhere. He didn't even know what "more" meant anymore, just that he wanted it. Bad.
-——
A/N: My first smut writing! Let me know if I'm doing a good job or just yapping.
• if you like the story, please leave a review.
• kindly push the story forward with your power stones.