The villa garage door slid open, and a low-profile black Maybach glided out into the freezing rainy night. As Akemi Miyano drove through the storm, she slowly shook off her dazed state and began to wonder why Yuu Hoshimiya had contacted her so suddenly.
Since the ten-billion-yen robbery, Yuu had barely reached out to her. For his sake and her own safety, she hadn't dared to contact him first. Despite her desperate longing to reunite with her sister, Akemi had never once pressured him. She understood the terrifying reach of the Organization; one wrong move could result in all three of them being slaughtered. Akemi was kind-hearted, but she wasn't foolish. She was, after all, the elder sister of the genius scientist Shiho Miyano. Even if she didn't possess Shiho's astronomical IQ, her intelligence was well above average—a fact proven by her successful planning and execution of the bank heist.
As she neared the destination, several theories floated through her mind, though most seemed far-fetched. The most plausible was that Yuu had fulfilled his promise and rescued Shiho. It would explain the urgent timing and the sudden contact. The only detail that didn't fit was his mention of a "child."
Shiho had shared tidbits of her research with Akemi, including the phenomenon of cellular regression in lab mice. Even knowing that, it was impossible for a normal person to imagine an eighteen-year-old beauty suddenly turning into a seven-year-old girl.
However, the moment Akemi saw the strawberry-blonde little girl, she realized the truth. Looking at a child who was the spitting image of her sister's younger self, it was impossible not to make the connection. She remained in a state of shock until Yuu carried the girl into the back seat of the car.
"Yuu-kun... the one in your arms is..." Akemi asked, her heart racing even though she already knew the answer.
"It's exactly who you think it is," Yuu replied, pausing for a moment. "I kept my promise. I'll explain the details later; for now, just drive."
"Right." Akemi steered the car back toward the villa. Throughout the drive, she constantly glanced at the rearview mirror. Yuu noticed her distraction, which was dangerous given the poor visibility of the rainy night.
"Akemi, focus on the road. I've already given her medicine; she's stable for now."
Not only had Yuu administered medicine, but he had also changed her clothes in the back seat. Her soaked knit sweater and lab coat would only worsen her condition. Children have weak constitutions, and Shiho's body was severely overtaxed.
Yuu didn't bother with modesty during the change; Shiho already had a terrible impression of him anyway. Without Akemi there to vouch for him, the girl would likely try to kill him the moment she woke up.
He couldn't help but notice that Shiho lived up to her reputation as a fashion-conscious young woman. Her red knit sweater was stylish enough, but the lingerie underneath was truly breathtaking. She was wearing an incredibly provocative set of semi-transparent gossamer lace. Because she had shrunk, the fabric hung loosely off her small frame, but it was enough to make Yuu's pulse quicken.
Yuu generally had no interest in actual children—which was why he had avoided Ayumi Yoshida—but Shiho was a different story. She was a "fake" brat. Mentally, she was a grown woman, and physically, she wasn't a complete blank slate either. Whether it was the APTX 4869 or just her natural genetics, she already showed the slight curves of puberty. Her chest had the softest budding peaks, and her secret garden, while smooth and hairless, had a distinct, fleshy pout—like a fresh, pale steamed bun filled with peach nectar. She looked delicious enough to eat.
Usually, such development wouldn't appear until the early teens, yet she stood at the height of a first-grader. Between Ayumi, who was mentally precocious, and Shiho, who was physically precocious, Yuu realized none of the little girls in this world were normal.
Back at the villa, Yuu handed the girl over to Akemi. Akemi's maternal instincts took over. She wiped Shiho's body down, fed her warm water, and applied fever patches. She was so worried she almost suggested a hospital, but Yuu reminded her that they couldn't risk it. If things got worse, he would call Seimi Asai, a professional doctor, to handle it.
Once Shiho's temperature dropped and her breathing evened out, Akemi finally sat down by the bed. "Yuu-kun, what happened? Why is Shiho a child?"
Looking into Akemi's beautiful ice-blue eyes, Yuu admired her composure. Aside from her distraction while driving, her performance tonight was flawless. She was calm, decisive, and understood the big picture. He began to explain the "premonition" he had—that Shiho would escape the Organization by shrinking herself.
Since Akemi already believed in his "magic" and "precognition," the explanation went smoothly. Akemi rolled her eyes playfully. "No wonder you were so confident. You knew she would escape on her own."
Yuu shrugged. "Did I fulfill the promise or not?"
Akemi opened her mouth to argue but found no words. He had technically taken a shortcut, but he had also saved Shiho's life tonight. Without him, she would have died of exposure in the rain. Akemi could only glare at him with an expression that looked more like a sultry invitation than genuine anger.
Yuu walked over and sat beside her, sliding a firm arm around her slender waist. He leaned in, his breath hot against her sensitive ear. "The promise is fulfilled. From now on, you belong to me."
Akemi shuddered as a deep crimson flush spread across her face. She gave a microscopic nod. She felt an immense debt of gratitude toward him, and even without their prior agreement, she felt she could only repay him with her body.
"In that case, let's do it," Yuu whispered.
The fire ignited by the sight of Shiho's petite, developing body was now raging. Since he couldn't touch the younger sister yet, he would use the older sister to quench his thirst. He had missed Akemi's mature, graceful body since their first time together. Moreover, he needed to finalize the "Contract" while her gratitude was at its peak.
Akemi looked hesitant. It wasn't that she didn't want him—she actually craved the feeling of being one with him—but her sister was unconscious right next to them.
"Yuu-kun, can we wait? I want to watch over Shiho tonight," she pleaded softly.
Yuu looked at the sleeping girl and then back at Akemi. "It's fine. You watch her, and I'll do you."
"What?" Akemi gasped, but before she could protest further, Yuu's mouth was on hers. Her weak "no" quickly turned into a high-pitched moan as his hands began to roam.
He pushed her skirt up and began to rub his hardened cock against her damp slit. Akemi's body betrayed her, her legs trembling as she felt the familiar fullness returning. She stopped struggling and let herself be swept away by the pleasure.
Yuu entered her in one smooth thrust, burying his "little Yuu" deep into her clutching warmth. Akemi's internal muscles were incredibly tight, her flower heart biting down on him with every thrust. He began to grind his hips, rotating the head of his cock against her softest spots. He could feel her womb trembling and dipping down to meet him as waves of honey-like juices flooded her canal.
Akemi let out a series of stifled, tantalizing whimpers, trying desperately not to wake her sister. "You're so thick... slower... ah..."
Yuu looked down to see her eyes glazed with lust, her tongue flicking over her lips in a trance of pure ecstasy. The sight of the dignified, black-haired beauty being reduced to a mess of desire only made him thrust harder. He didn't care if Shiho woke up; their relationship was going to be revealed eventually anyway.
"Ah! Ah!" Akemi's cries became more urgent. She wrapped her long legs tightly around his waist, pulling him in as deep as possible. Her mouth sought his, their tongues tangling in a desperate, wet kiss. As the friction intensified, the layers of tender flesh inside her milked him relentlessly.
Yuu licked her pink, cherry-like nipples while grinding into the very depths of her peach source. Akemi's body arched, her muscles twitching as she reached the peak of her climax. A torrential flood of juices erupted from her, drenching them both as she spasmed in his arms. In the throes of such bone-melting pleasure, she completely forgot that her little sister was lying only inches away.