The Agreement
The moonlight seemed unusually bright tonight. Maybe it was just my mood. Its soft glow illuminated the ruins, and Luna stood atop the debris of a collapsed building nearby, lightly tapping her feet. Balancing on a half-broken pillar and swaying her body, she looked almost like a carefree child.
It felt empty. Now that the long-cherished revenge was over, only a hollow emotion remained. What do I do now?
The goal that had defined her for so long had suddenly vanished. As that unfamiliar sense of helplessness began to spread, Luna suddenly felt a dull ache rising from deep inside her body. She looked down at her abdomen with a strange sense of wonder.
They had fucked like beasts. She had been taken like a beast. That was probably why the throbbing still lingered. Yet for some reason, she didn’t mind the pain at all. If anything, she felt a pang of regret that it was slowly fading away.
As she unconsciously stroked her lower belly, Luna finally seemed to realize something. A faint smile curved her lips. She had found a new purpose—one that would fill the emptiness inside her.
With the vivid memory of his touch still lingering, Luna quietly twisted her waist. A sharp throb immediately flared from the muscles in her buttocks.
“Ugh…”
She flinched, her face twisting slightly. Every time she tried to sit, the traces he had left on her skin came rushing back without warning. Because of that, she had a feeling that matching his tastes in the future might not be as simple as she thought.
Still, Luna didn’t mind. If anything, she grew more curious about how she could arouse him even further.
“Ha…”
Before she knew it, her hand had slipped between her thighs. Her fingertips brushed against her most intimate place through the thin suit, and Luna let out a short, involuntary moan.
Even after being filled so many times, the thirst remained, like an unquenched craving. If anything, she felt herself becoming more and more addicted.
“Yuto… haaang…”
Whispering his name, her fingers slid deep into her slick folds. She could feel the semen that still hadn’t fully leaked out mixing with her own juices. Even though she had tried to wipe away the evidence, the sticky fluid trickled down her thighs again. Luna pushed it back inside with her fingers, as if reluctant to waste even a drop. Deeper. Even deeper.
“Haa… haa…”
What if Yuto saw her like this? Would he be disappointed and call her a pervert? Or would his own desire flare up again, just like hers?
The thought that either reaction would be fine made Luna tremble as she smiled beneath the moonlight. She wished Yuto could see her right now. She wanted to see his cold, lowered gaze as he asked her sternly what she was doing. And then, in that contemptuous stare, to be taken like a beast once more… Just imagining it sent a thrilling excitement racing through her entire body.
“Hngh… ah…!”
The moment her fingers reached the deepest spot, her whole body shuddered. Heat erupted from within as if something inside her had burst. Her hips bucked involuntarily, her entire body clenching tight. The world before her eyes shattered into pure white. A sharp thrill pierced through her core, and a breathless cry escaped her lips.
“Haa… haat… aaah…”
Under the moonlight, Luna’s body collapsed limply. Sweat trickled slowly from her neck down past her collarbone, and an irrepressible smile played on her lips.
She was still savoring the afterglow of her climax when she heard footsteps from behind.
Luna turned her head reflexively. The figure emerging from the moonlight wasn’t Yuto. It was Yuzuki.
It was unexpected, but Luna took a short breath, smoothed the half-raised corner of her mouth into a composed expression, and greeted her with a welcoming face.
“Hello, Yuzuki. I didn’t expect to run into you here, but it’s nice to see you anyway.”
“…I’m not happy to see you at all.”
Yuzuki’s response struck like a sharp arrow. But it didn’t seem to be because she had caught Luna masturbating. What Luna sensed from her was pure, sticky feminine resentment.
Thanks to that, Luna realized it without difficulty. Yuzuki had found out what had happened between her and Yuto.
But where had she picked up the clues? From Yuto’s expression? The scent lingering on his body? Or was it simply Yuzuki’s intuition?
Luna maintained a calm facade while looking at the icy Yuzuki, but deep down, she was curious too. How had things gotten this deep?
At first, it had been nothing more than a game. Curiosity. Even a pebble tossed out of boredom. She had been interested in Yuto, yes, but she never imagined it would turn into such uncontrollable longing and obsession.
Maybe this was what first love felt like. The sweet yet destructive emotion she was feeling toward the opposite sex for the first time in her life. It had rushed in with overwhelming intensity, and at some point, Luna’s entire world had begun to revolve around Yuto.
That was why, even now, she had no idea how she should respond to Yuzuki. No matter what, Yuzuki was someone precious to Yuto. If she tried to push her aside out of selfish greed, she had no way of knowing how Yuto would react.
Step. Step.
While Luna was lost in thought, Yuzuki walked forward silently and stopped right in front of her—close enough that their breaths mingled. Their chests were nearly touching.
The moment she met Yuzuki’s face head-on, Luna felt a strange emotion.
“…I guess it really is because they’re siblings. The shape of their eyes and faces is oddly similar.”
“…What?”
Yuzuki frowned. In that instant, Luna caught a glimpse of Yuto in her expression. If Yuto glared at her coldly, would it feel like this? Just thinking about it made something inside her tighten.
“For some reason, I think I’m going to like you even more…”
“W-what are you saying!”
Startled by Luna’s sudden remark, Yuzuki stepped back, her face flushing. A mixture of embarrassment and anger crossed her features. But it only lasted a moment. Yuzuki took a breath and composed herself, as if reminding herself why she had come here.
She hadn’t come to be toyed with by Luna’s teasing. She had a purpose.
Yuzuki looked Luna up and down. The red marks on her neck, the knees that trembled slightly even though she was just standing, and the unfamiliar garment wrapped suspiciously around her lower body. That alone was explanation enough.
No—from the moment suspicion had begun, everything had already started to make sense.
As if reading Yuzuki’s thoughts, Luna smiled sweetly.
“Are you curious about what Yuto and I did, Yuzuki? Want me to tell you?”
“…What did you do?”
Luna smiled with her eyes and answered in a low voice.
“We had sex. Like absolute beasts.”
Her words were so direct that the air itself seemed to freeze for a moment. Yuzuki flinched, her eyes widening as she stared at Luna. The way she desperately tried to keep a blank expression only made the emotional turmoil inside her even more obvious.
“…Ugh.”
In the end, she couldn’t maintain her composure and bit her lip. Yuzuki had never expected Luna to admit it so openly.
Even so, Luna simply watched her quietly. There was no shame, no excuses, no apologies—just a curious gaze wondering how Yuzuki would react. That relaxed attitude was infuriating. And the fact that she could guess why only made her want to cry.
But Yuzuki didn’t lose control. She didn’t raise her hand to slap Luna’s cheek, nor did she shout or explode in rage. Instead, her eyes grew even colder. In that chilly silence, she finally spoke, her voice heavy.
“I see. If Yuto had to choose someone, maybe it’s a good thing it was you, Sakuragi.”
Luna tilted her head at those words. For a moment, she couldn’t understand what she meant.
“What do you mean?”
Yuzuki took a step closer, fixing her gaze directly on Luna’s eyes.
“Because it’s you, Sakuragi, I don’t have to pretend that my relationship with Yuto is normal. You already know everything about us, don’t you?”
Luna narrowed her eyes, turning Yuzuki’s words over in her mind. By “normal relationship,” she probably meant the sibling relationship they maintained for the sake of the outside world.
“…Hmm.”
Finally, Luna couldn’t hide her emotions any longer. A delighted smile spread across her face. The emptiness was fading. Instead, anticipation for what was to come was blooming. Was this what they called the vitality of life?
“So… is that all you wanted to say, Yuzuki? If you want, you can curse at me or slap me.”
Luna had no intention of getting into a messy fight with Yuzuki. She would rather let her vent her feelings here and now.
But Yuzuki frowned in disgust and shook her head, as if asking what nonsense she was spouting.
“No thanks. There’s something more important I need to talk about, so listen carefully.”
Yuzuki took a moment to steady her breathing, then looked straight at Luna and continued.
“Since things have come to this, we need at least some minimum rules between us.”
Luna tilted her head again, her eyes sparkling with interest at what Yuzuki might say next.
“Rules…? What kind?”
“Simply put… we won’t completely push each other away. Jealousy is allowed, but interference is forbidden. Something like that.”
Understanding the intent easily, Luna smiled and murmured.
“…I see. It’s like a kind of romantic agreement, huh?”
“Something like that. Anyway, no matter what you do, I don’t want to let go of Yuto. What about you?”
At the question, Luna wiped the smile from her face for a moment. This seemed like a time to be serious.
“Same here. Maybe because it’s my first love, I don’t want to let him go either.”
Yuzuki’s eyes wavered slightly at those words.
“…First love?”
“Yeah. It’s the first time in my life I’ve ever felt this way about someone.”
Luna’s face as she nodded was so pure, like an innocent young girl who had yet to be tainted by the world. Perhaps that was why, after a brief silence, Yuzuki managed to pull herself together. She straightened her expression and held out her hand.
“Fine. This is a temporary agreement for now. We’ll talk about the details later.”
Luna stared at the offered hand for a moment, then placed her own on top of it. Beneath the moonlight, the shadows of the two women slowly overlapped.
The moment I leaned back against the seat in the rear, my eyelids grew heavy as lead. All the tension and exhaustion I had been holding back came crashing down at once, and a wave of utter fatigue washed over me, as if my body were sinking into the floor.
As my consciousness began to drift, I unknowingly rested my head against the window and started dozing off.
But then—
“Mister. I have something to say. Is that okay?”
Luna’s voice from the seat beside me was clear. I cracked my eyes open halfway and looked at her, wondering what she wanted to talk about. She glanced at me briefly, as if conscious of my gaze, then spoke.
“I think I might be able to help you with the Dearest Project.”
The instant those words left her mouth, the car that had been driving straight ahead suddenly lurched violently. The steering wheel had been jerked hard, the vehicle swerved left and right, and the tires scraped against the road with a horrible screech.
The jolt snapped me wide awake. All traces of sleep vanished. I immediately looked at my father, who was gripping the steering wheel. His hands were visibly trembling. His eyes were still fixed on the road, but his pupils were clearly tense.
Finally, Father turned to look at Luna in the back seat and said,
“…What are you suddenly talking about? And do you even know what that is?”
“Would I say it if I didn’t know? Anyway, thanks to me, you’ll be able to start the project sooner. Isn’t that great?”
At Luna’s words, Father nervously glanced toward Yuzuki, who was sitting in the passenger seat. But Yuzuki continued staring out the window, speaking as if she had already known about this conversation the whole time.
“Dad. We’ve already sorted that matter out among ourselves, so you don’t need to worry so much.”
“……What?”
Father fell silent, his face going blank. It was an expression I had never seen on him before. And I was probably making a similar face myself.