The walk back from the ramen shop was different.
The air between them, usually thick with tension or teasing, now felt charged with a strange, exhilarating honesty.
As they stepped out into the bustling street, Makoto's hand found hers, their fingers lacing together in a gesture that felt both natural and profoundly forbidden.
"So…" he began, his voice a low murmur, "About that new deal you mentioned... Is there a payment plan that doesn't involve money?"
Yuna's eyes narrowed. She stopped dead on the sidewalk, wrenching her hand from his grasp.
For a heart-stopping moment, he thought he'd pushed too far, that the fragile truce they'd just formed had shattered.
Then, her smile returned, a slow, lethally sweet curve of her lips.
"Oh? You want to try our new deal? I think we can call it a... girlfriend experience," she purred. "Fine."
In a single, fluid motion, she shoved him against the grimy wall of a nearby building, her small frame pinning him with a surprising strength. "The payment plan is..."
Her hand slipped into his pocket, not for his wallet, but to close around his already hardening cock through the fabric of his jeans. "…you cook me dinner. With candles. And you have to say three things out loud while we eat."
She counted them off on her fingers, which were still sticky and smelled faintly of ramen broth.
"First: My Yuna is cuter than any gacha waifu."
"Second: I'm lucky to have such a perfect little stepsister."
"Third…" Her breath ghosted over his lips, a warm, tantalizing puff of air. "…I want to creampie you again tonight."
She pulled back with a viper's grin, her eyes glittering with a triumphant, malicious glee. "Say all three without choking on your own shame. Then maybe…"
Her thumb rubbed slow, deliberate circles over his trapped erection. "…I'll let you hold my hand while we walk home. Like a real couple."
A giddy, reckless joy surged through him. This was a game, but the stakes were different now.
It wasn't about money or blackmail anymore. It was about something far more dangerous.
"Fine," he giggled, the sound a little breathless. He pushed off the wall, grabbed her hand, and pulled her toward a nearby shopping mall.
"I look forward to it. Let's buy groceries for dinner, and maybe some new clothes for you." He chuckled, a genuine, happy sound. "Real clothes, I mean."
Yuna froze mid-step, a genuine shock flashing across her face before she erupted into mocking laughter. "Real clothes?"
She hooked her arm through his with a terrifying sweetness. "Aw, is big bro trying to pretend I'm not his personal sex doll?"
As they entered the brightly lit mall, she dragged him, with a single-minded, predatory focus, straight toward the lingerie section.
"But fine." She held up a scandalous lace teddy against herself, the sheer black fabric a stark contrast to her pale skin.
"If you're buying… I'll wear whatever boring sweater you pick out." Her smile turned venomous.
She leaned in as a nervous-looking salesgirl approached, her voice rising to a conspiratorial whisper that was loud enough for the poor girl to hear perfectly.
"My brother says I dress too slutty! Can you believe it?" The salesgirl paled and scurried away. Yuna grinned, a triumphant, wicked thing.
"Now. About those three things you owe me…"
She picked up a pair of crotchless panties from a nearby display and shoved them into his hands. "Say the first one. Now. While you're holding these."
Her eyes glittered with a dark, malicious light. "Go on!"
Makoto's face burned. He could feel the stares of the other shoppers, a sea of silent, judging eyes.
But the dare, the sheer, audacious challenge in her gaze, was irresistible.
"Fine, fine," he grumbled, a smile tugging at his lips despite himself. "You're enjoying this way too fucking much."
He took a deep breath, threw the offending panties into their shopping basket, and yelled, his voice cracking with a mixture of shame and exhilaration, "My little stepsister Yuna is cuter than any gacha anime waifu!"
The silence that followed was deafening. An elderly woman clutching her pearls nearby looked like she was about to have a heart attack.
"Happy now?" he grunted, his face a furious shade of red.
Yuna's grin was pure, unadulterated evil as she clapped mockingly. "LOUDER, BIG BRO! I don't think the people on the escalator heard you!"
She pointed a finger at the horrified elderly woman. "Tell granny over there, too!"
Then, in a flash, she was in his space, her hand grabbing his collar and yanking him down to her level.
"Now the second one," she hissed, her breath hot against his ear. "Say it like you mean it. Or…"
Her other hand drifted down to the crotch of his pants, a silent, damning threat. "…I'll make you beg for it in front of the security cameras."
She released him with a shove that sent him stumbling toward the terrified cashier. "Go on. Pay for my new real clothes."
She dropped the crotchless panties and the sheer teddy onto the counter with a definitive thud. "And while you're at it…"
Her voice dropped to a venomous whisper that only he could hear, a final, public humiliation. "…tell the cashier how lucky you are to have such a perfect little stepsister."
He was trapped. Utterly, completely trapped.
With a sigh of defeat, he took out his credit card and looked the poor, trembling cashier directly in the eye. He forced a nonchalant, conversational tone. "You know, I'm really, really lucky to have such a perfect little stepsister."
The cashier's eyes widened in horror. She fumbled with the credit card machine, her hands shaking.
Makoto quickly grabbed the bag of illicit goods and Yuna's hand, pulling her away from the scene of the crime.
"Well?" he asked, his voice a little breathless. "Did I earn myself some public hand-holding, at least?"
Yuna cackled, a demonic, triumphant sound, as he dragged her away, the cashier's horrified stare burning into his back.
"Oh, you earned it," she purred, interlacing her fingers with his with a mocking sweetness.
Her small hand felt deceptively innocent in his, a stark contrast to the way her nails were digging crescent moons into his skin.
She swung their joined hands like a child as they passed a group of high school girls, who immediately started whispering and giggling behind their hands.
"Look, big bro!" she announced loudly, her voice ringing with false innocence. "We're holding hands! Just like a REAL couple!"
As they neared the grocery section, she leaned in, her breath a warm, tickling sensation against his ear.
"Two down, one to go." Her free hand drifted dangerously low, resting on his hip with a possessive weight.
"But save the creampie confession…" Her teeth grazed his earlobe, a sharp, thrilling promise. "…for when I'm riding you later. Over candlelight."
She skipped ahead, still clutching his hand like a leash, her grey twin-tails bouncing with a cheerful, wicked energy. The little demon.