Chapter 1

Jacob had always been fit—not a gym rat, but lean, naturally toned from a fast metabolism and a casual love of hiking. Kotoe had met him during undergrad, and now, as a law student buried in coursework, she found solace in their small routines together. But there was something new creeping into their relationship, something that stirred inside her whenever she looked at him lately.

It had started innocently enough. Between her studies and his long shifts at the office, takeout became their norm. Kotoe had always been a good cook, but now she used it as a stress relief, whipping up rich, comforting meals to share with Jacob. He never questioned the extra butter in the sauces, the heavy cream in the soups, or why she always served him just a little more than herself.

At first, she barely noticed the changes—just an extra softness to his stomach when he stretched, the way his shirts seemed to cling a little tighter after a big meal. But one night, as he sat on the couch, lazily rubbing his belly after finishing off the oversized portion of tonkatsu she’d made, something clicked. His stomach, no longer flat, pushed slightly over the waistband of his jeans, a small curve forming where once there had been none. And he didn’t even seem to notice.

Kotoe did.

A warmth bloomed deep inside her, something dark and possessive. He looked… comfortable. Indulgent. Softer in a way that made her want to feed him even more.

From then on, she stopped leaving things to chance.

She brought him surprise lunches at work accompanied by decadent desserts from the bakery he liked. At home, she experimented with richer recipes, feigning innocence when he groaned about how stuffed he was, pretending not to notice how often he unbuttoned his jeans after dinner.

“Oh, I guess I did go a little overboard,” she’d giggle, pressing a kiss to his cheek. “But you liked it, right?”

And he always did. Jacob was oblivious to her intentions, too distracted by the sheer pleasure of the food to realize he was outgrowing his wardrobe.

The first time she caught him shirtless, really looking at him, it sent a thrill through her. His abs were long gone, replaced by a soft curve that jiggled slightly when he moved. His thighs had thickened too, his arms rounding out, losing the sharp angles of his former frame.

“Babe, do you think I’ve gained weight?” Jacob asked one night, standing in front of the mirror, poking at the softness at his waist.

Kotoe wrapped her arms around him from behind, pressing against his back, feeling the warmth of his fuller frame. “Maybe a little,” she murmured, running her hands down to squeeze his belly gently. “But I think you look really good.”

His ears turned pink, and he chuckled. “Guess I’ve been eating too well.”

She only smiled, nuzzling into him. He had no idea.

Kotoe became bolder. Jacob remained oblivious, too busy enjoying the endless stream of rich, home-cooked meals and indulgent takeout to notice the careful orchestration behind it all. If he ever did suspect, he never voiced it—after all, she was just a loving girlfriend who liked to cook for him.

She started grocery shopping alone, filling their kitchen with calorie-dense snacks and pre-made meals he could grab at work. She swapped his usual black coffee for lattes laden with cream and sugar, always making sure to have a fresh pastry or two on hand in the mornings. When they ate out, she’d playfully insist they get appetizers and dessert, always acting like it was a treat for herself—but Jacob, ever the chivalrous boyfriend, always helped her finish everything.

It was working faster than she’d anticipated.

One evening, he flopped onto the couch after dinner, groaning as he rubbed his belly. Kotoe sat beside him, eyes glinting as she took in the way his shirt stretched tightly across his midsection. It barely fit anymore, riding up enough to expose the soft curve of his stomach. His jeans had become a battle to button, and lately, he’d been leaving them undone around the apartment.

“I really shouldn’t have eaten that much,” he mumbled, patting his belly absentmindedly.

Kotoe leaned in, resting a hand on his rounded stomach, feeling the warmth and heaviness of it. “But it was so good, right?” she cooed.

He exhaled, sinking deeper into the cushions. “Yeah… so good.”

She traced slow circles against his belly, feeling how soft it had become under her touch. “Mmm, I love seeing you full like this,” she murmured. It was the first time she’d said it out loud, her true thoughts slipping past her lips.

Jacob cracked an eye open, looking at her with a lazy, satisfied smile. “Yeah? You like having a food coma boyfriend?”

Kotoe smirked, shifting closer until she was straddling his lap. She could feel the difference in him—how plush his middle had gotten, how his thighs felt thicker beneath her. She gave his stomach a gentle squeeze, biting her lip.

“I love it,” she admitted, voice dropping to a near whisper.

Jacob chuckled, but the blush creeping up his neck told her he wasn’t entirely unaffected. “Guess I’m gonna have to hit the gym again soon,” he muttered.

She pouted, leaning down to press a kiss to his jaw. “Mmm… but you look so good like this,” she breathed, letting her hands roam, pressing into the growing softness of his body.

His breath hitched—whether from her words or the way she was touching him, she wasn’t sure. But Kotoe knew he wouldn’t be going to the gym anytime soon, not if she had anything to say about it.

---


Kotoe straddled Jacob's lap one night, her hands running over his sides, feeling every inch of his expanding body. He was softer now, his muscles buried under a plush layer of fat. The realization sent a thrill through her. She leaned in, pressing a kiss to his lips, slow and lingering.

“You’re getting so big for me,” she murmured, her fingers digging into his love handles. “I love it.”

Jacob chuckled, though there was a dazed look in his eyes. “You really don’t mind that I’ve put on weight?”

She smiled, slow and knowing. “Mind? Baby, I want you bigger.”

His breath caught, but she didn’t give him time to process. She rolled her hips against him, grinding just enough to make him shudder. “I want you stuffed full every night, too heavy to move, too soft to resist me.” Her voice was sweet, but her grip on his sides was firm, possessive.

Jacob swallowed hard. “Kotoe, that’s…” He trailed off, his hands instinctively settling on her waist.

“Hot?” she supplied, tilting her head, a teasing glint in her eyes.

His silence told her everything.

She leaned in, lips brushing his ear. “Let me take care of you,” she whispered, running a hand over his belly, pressing down just enough to make him groan. “No more worrying about your weight. No more diets. Just you, eating every bite I give you like a good boy.”

He exhaled sharply, and she felt him melt beneath her, his grip tightening around her hips. She knew she had him now.

“You trust me, don’t you?” she purred.

“…Yeah,” he admitted, voice low.

She smirked. “Then let me do this for you.”

From that moment on, Jacob wasn’t just gaining weight—he was growing under her control.

She monitored his meals, made sure his portions were always excessive, and cooed in delight when he cleaned his plate. She took charge of his wardrobe, replacing his shrinking clothes with stretchier, looser options that would make it easier for him to grow into. His complaints—mild at first—were easily soothed with sweet kisses and full stomachs.

At first, Jacob still tried to protest. “Babe, I’m getting huge,” he groaned one evening, eyeing his reflection in the mirror. His belly was undeniable now—a heavy, rounded thing that jutted forward, pressing against the waistband of his sweatpants.

Kotoe slinked up behind him, wrapping her arms around his thickening frame. “I love it,” she murmured, pressing her body against his back. “You look perfect.”

---

Kotoe didn’t just want Jacob bigger—she wanted to see just how much she could change him. While she made sure his every meal was decadent, every snack within reach, she took the opposite path for herself. She started waking up early for runs, lifting weights at the gym, fine-tuning her body while Jacob, under her careful manipulation, softened more with each passing week.

She made sure he noticed.

One morning, Jacob shuffled into the kitchen, rubbing sleep from his eyes, his belly hanging out of his undersized t-shirt. Kotoe, fresh from a workout, stood at the counter in nothing but a sports bra and tight shorts, muscles gleaming with sweat. She smirked at him as she poured herself a protein shake.

“Morning, sleepyhead,” she teased, flexing her arm as she brought the shake to her lips. Her bicep, firm and well-defined, stood in stark contrast to his thick, softened frame.

Jacob blinked at her, still groggy, but his eyes trailed over her body—lean, strong, sculpted—before flicking down to himself, to the round belly that now dominated his middle.

“Damn,” he muttered, running a hand over his stomach. “You’re getting ripped, and I’m just getting… fat.”

Kotoe’s smirk widened. She set her shake down and sauntered toward him, her muscular thighs flexing with every step. “Not just fat,” she purred, placing her hands on his plush sides and giving them an appreciative squeeze. “Soft. Squishy. Weak.”

He swallowed hard as she pressed against him, making sure he could feel the difference—the firmness of her abs against his growing gut, the way her strong arms wrapped easily around his thickening frame.

“I dunno…” he started, hesitant. “I should probably—”

She cut him off with a slow, teasing grind of her hips against his, her fingers trailing up his stomach, lifting the heavy softness just enough to make him feel how much he’d changed.

“You should probably eat,” she whispered against his ear. “Breakfast is already on the table. I made extra, just for you.”

Jacob exhaled sharply, whatever protest he’d been about to make vanishing as Kotoe leaned in, pressing a slow, taunting kiss to his lips.

That was all it took.

He let her guide him to the table, where a plate piled high with buttery pancakes, eggs drowning in cheese, and crispy bacon waited for him. She sat across from him, legs crossed, sipping her protein shake as she watched him dig in.

By the time he was finished, his belly was round and tight with food, and Kotoe wasted no time climbing into his lap, straddling his softened thighs, her hands tracing the firm swell of his overfed gut.

“Mmm, so full,” she cooed, pressing down slightly, making him groan. “But I love feeding you so much...”

She leaned in, lips brushing his jaw, her voice dripping with sweet, wicked satisfaction.

“Guess I’ll just have to help you work up another appetite.”

---

Kotoe loved the way his belly swayed with him, how stairs left him winded, how his shirts refused to stretch over the thick curve of his gut.

But more than that, she loved emphasizing the growing contrast between them.

She had never been so strong. The gym had become her temple, and her body reflected it—her upper back and shoulders visibly muscled, her abs sculpted and tight, her thighs powerful. Every time she looked at Jacob, sinking deeper into softness, she felt an intoxicating thrill of control.

One afternoon, as he stood in the living room struggling to pull a t-shirt over his belly, Kotoe crept up behind him. She wrapped her arms around him—except this time, instead of a soft embrace, she lifted him.

“Woah—Kotoe!” Jacob yelped as his feet left the ground.

She grinned, easily holding him in a tight bear hug, her biceps flexing against the plushness of his body. “Damn, babe,” she teased, finally setting him down, her hands lingering on his sides. “I remember when you used to be the strong one.”

Jacob huffed, adjusting his shirt, which barely covered his belly. “Okay, okay, you’ve been hitting the gym hard. I get it.”

Kotoe smirked. She wasn’t done.

She stepped in front of him and grabbed his arm, lifting it like she was inspecting it. Where once there had been firm muscle, now there was only soft flesh. She gave it a gentle jiggle, biting her lip as she watched it bounce.

“Mmm,” she hummed, eyes flicking up to meet his. “Your arms used to be so hard… now they’re just so squishy.”

Jacob’s face burned red, but before he could respond, she moved to his chest, grabbing a handful of the soft weight there, squeezing playfully.

“And these…” she teased, lifting the plush flesh of his pecs. “Getting bigger than mine now.”

She flexed her arms in front of him, then pressed his hand against her abs, letting him feel how solid they were.

“Babe…” he muttered, swallowing hard.

Kotoe grinned, stepping closer, letting the contrast sink in—the firmness of her body against the softness of his. She drummed her fingers on his belly, pressing lightly into the roundness, making him shiver.

“You used to be able to pin me down so easily,” she whispered, her voice dripping with amusement. “But now… I bet I could take you down without even trying. I'm... stronger than you now, Jacob.”

Jacob exhaled sharply, caught between embarrassment and something else—something that made him squirm under her touch.

Kotoe leaned in, her lips brushing his ear.

“And I love it.”

One night, as Jacob sat on the couch, rubbing his overstuffed belly after yet another massive dinner, he muttered, “I'm having fun with all this weight gain stuff, babe, I really am. But seriously, I should hit the gym again soon…”

Kotoe, perched on his lap, barely let him finish before tilting his chin up with her finger, her eyes dark with amusement.

“No,” she said simply, voice firm.

Jacob blinked. “…No?”

She smirked. “No working out. No dieting. No more worrying about that kind of thing. That’s my job now.”

Jacob’s face flushed. “But I—”

She silenced him with a slow grind of her hips, pressing his overfed body deeper into the couch. Her hands roamed his chest, gripping the softness there, then trailing down to his belly, squeezing just enough to make him feel how heavy it had gotten.

“I like you this way,” she murmured, pressing a kiss to his jaw. “I like how big you’re getting for me. So no more talk about working out. Got it?”

Jacob sensed the lopsided power dynamic shifting even further in her favor, but somehow, didn't feel any desire to resist. He just exhaled, sinking into her touch. “…Got it.”

---

Kotoe had chosen the restaurant for a reason—all-you-can-eat, generous portions, and a relaxed enough atmosphere that Jacob wouldn’t hesitate to overindulge. And he had, stuffing himself on multiple helpings while she sat across from him, nursing a light salad and sipping water, watching with satisfaction as he sank deeper into post-meal sluggishness.

Jacob leaned back in his chair, rubbing the firm swell of his belly, his shirt riding up just enough to expose the softened curve. “God, I’m stuffed,” he groaned, eyelids heavy.

“Mmm, you're such a good boy for me,” she cooed, reaching across the table to hold his plump hand, which she noted no longer had any trace of the veiny, masculine roughness it once did.

Before Jacob could respond, a group of men walked past their table—broad-shouldered, jacked, aggressively masculine. The type of guys Jacob used to look like. One of them did a double take at Kotoe, his lips curling into a cocky smirk.

“Damn, you’re looking fine,” he said, ignoring Jacob completely. “What’s a girl like you doing with this?” He nodded toward Jacob’s stuffed, sluggish form.

Jacob stiffened, but Kotoe just quirked a brow, taking a slow sip of water.

Another guy in the group snickered. “Dude, looks like she’s his caretaker, not his girlfriend.”

Jacob flushed deep red, shifting uncomfortably in his seat. “Hey, man, just—just back off,” he muttered, but his voice lacked the edge it might’ve had a year ago.

The first guy laughed, stepping closer. “Or what?”

Jacob tried to stand, but his belly was full, his movements slow and clumsy. The guy shoved his shoulder, knocking him back into his chair. The force of it sent a ripple through his soft gut, and Kotoe saw the way Jacob’s face twisted—not just in embarrassment, but helplessness.

That was it.

Before the asshole could even register what was happening, Kotoe moved.

Fast.

A sharp, controlled elbow to the gut—right into his core, knocking the wind from his lungs. He doubled over with a choked gasp. Kotoe grabbed his wrist, twisting it with just enough force to make him yelp before shoving him back. He stumbled, wide-eyed, clutching his stomach.

The restaurant had gone silent.

Kotoe turned, eyes cold as she fixed them on the rest of his group. “Any of you fuckers want to try something next?”

No one moved.

She huffed, rolling her shoulders, the definition in her arms sharp under the restaurant’s dim lighting. “Didn’t think so.”

She turned back to Jacob, who was still frozen in his seat, his face caught between admiration and shame. She sighed, stepping forward, her expression softening just a fraction.

“C’mon, babe,” she murmured, holding out a hand. "Are you okay?"

"Y-Yeah.. I think so". His voice sounded small as he rubbed his shoulder where the man pushed him. She pulled him up effortlessly, steadying him as he wobbled slightly from the weight of his full stomach.

Kotoe wrapped an arm around his thick waist, her grip firm, supportive. Then she shot one last glare at the group of men.

“Try that again,” she said coolly, “and you’ll be leaving in a stretcher.”

And with that, she led Jacob out, holding the door for him as he meekly looked downward.

Once they were outside, Jacob exhaled, running a hand through his hair. “Shit… I can’t believe you just—”

Kotoe smirked, grabbing his chin and tilting his gaze up to meet hers.

“I told you, baby,” she murmured, pressing a lingering kiss to his lips. “You don’t need to fight for yourself anymore. That’s my job now.”