It was a Saturday evening, the first clear day in a long time.
Already this late...?
Shito Manaka saw the wall clock approaching 6 PM and felt a sinking feeling. Self-loathing for wasting such a precious day off.
What should I have for dinner...? Going out is too much trouble... Maybe a convenience store?
Living alone inevitably led to neglecting herself.
The price of having spent the entire day lazing around her apartment was catching up to her. She was hungry but couldn't bring herself to eat, yet she couldn't afford to skip a meal—the feeling was utterly uncomfortable.
Sigh...
Still, she steeled herself, heaved her heavy body off the couch, and was about to head to the neighborhood convenience store when the doorbell rang.
Who could that be? I hope it's not a salesman.
But it might be a package for her roommate, so she couldn't ignore it. She checked the visitor through the intercom.
A familiar voice came from the intercom. My heart lurched, nearly making me retch.
"Ryosuke..."
When Manaka recognized the visitor, she was stunned. She agonized over whether to answer him.
Just moments earlier, she'd been fretting over trifling things like hunger and the inconvenience of going to the convenience store. Now, she resented that past self for such trivial worries.
But she'd already answered the intercom.
She couldn't play hard-to-get now, and she couldn't just send him away.
After all, this junior by five years, her younger brother, spoke with such eloquence that he didn't seem like a student at all. He wasn't someone Manaka could chase away with mere words.
If he keeps developing like this, he'll probably become a master marriage scammer.
He was the kind of man who genuinely worried his elder sister.
"..."
Bracing herself, Manaka headed to the entrance.
As she reached the door, her gaze fell on the full-length mirror built into the shoe locker.
(...)
No makeup. A plain T-shirt. Sweatpants. Her appearance couldn't be more casual.
Well, of course.
Manaka Shito had always been blessed with striking features: fine skin, delicate features, and long, curled eyelashes. She was undoubtedly classified as a "beauty." Her figure was so good that even her loungewear looked stylish.
Without makeup, she even looked younger than her age, but there was no need to worry about that. Still, the fact remained that she considered her current attire "sloppy."
What should I do...?
It was too late to change now, and putting on makeup was out of the question.
...Wait.
After all, standing beyond the door was just her younger brother-in-law. There was absolutely no need to dress up—
"...!"
Manaka hastily smoothed her messy hair and unlocked the door.
"Hey, sis. Long time no see. I just dropped by."
"Just dropped by? You..."
Ryosuke's friendly demeanor was unapologetic, even though his sudden visit was clearly unexpected.
He must have known Manaka's address, but this was the first time he'd ever come to her apartment.
It had been a year and three months since Manaka moved out.
Just when she was starting to forget about Ryosuke...
"What do you want?" Her voice hardened.
"Hmm? I figured you hadn't been eating properly. So I thought I'd let my personal chef flex his skills for the first time in ages."
He held up the heavy plastic bags from the supermarket, filled with ingredients for dinner.
"...Don't just barge in like this."
"It's fine. We're siblings, after all."
"That—"
Though their relationship was technically through marriage, they were still siblings.
But they certainly weren't normal siblings.
"...What would you have done if someone else was here?"
"Isn't your older brother-in-law on a business trip?"
"How did you know?"
"It's not like I looked it up or anything. He contacted me yesterday. Said he got a long-term assignment and to take care of my older sister. 'Make sure she doesn't die,' he said."
Manaka was living with her fiancé.
They had been dating even before she became Ryosuke's older sister-in-law. They started living together in this apartment when they entered university and both secured job prospects.
And indeed, he had been on a business trip since yesterday. A cheerful, lively man with a passion for his work.
This charming younger brother-in-law quickly became close with Manaka's fiancé. Even now, they still keep in touch casually.
That... terrifies Manaka beyond endurance.
When will Ryosuke finally reveal the truth? Will Manaka's sins be exposed? The thought terrifies me.
Yet Ryosuke himself doesn't seem to harbor any such concerns. He shows no signs of guilt or resentment towards me.
Despite living closer to him than anyone else, I still can't understand his true feelings...
"Speaking of cooking... How is Marin managing dinner?"
I despise myself for bringing up my younger sister as a cowardly way to change the subject. Still, my worry for her isn't entirely feigned, since neither of our parents is home much.
"I made extra at lunchtime, so she's fine. Marin's much more responsible than I am, you know."
"..."
"Oh, and she misses you. You should come home and visit more often."
"That..."
You know better than anyone why I don't want to go back.
Manaka wanted to press him, but she held her tongue.
Instead, she changed the subject.
"You went shopping... What were you planning to do if I wasn't home?"
"I figured I'd bring home the fresh stuff and hang the rest on the door."
"..."
He was far more domesticated than her own mother. His considerate nature was both infuriating and... endearing.
"Anyway, come inside. People will get the wrong idea if you stay out here."
"Haha!"
His laid-back attitude was truly adorable. It made her wonder who was the older sibling.
Still...
He's gotten taller again.
Manaka wasn't short by any means, but her average height for a woman still couldn't compare to Ryosuke's above-average height for a man.
Yet when they first met, Manaka had been taller than him. In the blink of an eye, they'd reached the same height, and now Ryosuke was a full head taller.
He's grown up.
The thought stirred something within Manaka, something beyond her feelings as his elder sister.
*****
"Wow. Isn't this past its expiration date by more than a month?" Ryosuke remarked casually as he rummaged through the refrigerator with the ease of someone at home.
"I-I was planning to throw it out on the next trash day," Manaka stammered.
"...And then a month passed while you were 'planning'?"
"J-just leave it alone! Don't go snooping through other people's refrigerators!"
"Older Brother-in-law can be so careless sometimes. As his younger brother, I can't help but worry."
"Mind your own business..."
"Huh. And you call yourself my brother?" Ryosuke retorted, his voice low. He was crouched in front of the refrigerator, only turning his head to snap back.
"Older Sister, do you even understand your position?"
His sharp gaze pierced Manaka. Her heart began racing. Until Ryosuke continued speaking, she felt like a frog frozen under a snake's glare.
But then...
"Older Sister, do you really think you grew up on someone else's cooking? Because of you and Marin, I seriously considered getting a chef's license for a while."
"W-what...? People have their own strengths and weaknesses, you know!"
That was all she could muster.
Her heart was still pounding, but she felt a slight relief when Ryosuke turned back to rummaging through the refrigerator for ingredients.
But...
Ryosuke quickly lowered his voice again, grumbling behind her.
"...Maybe I should have had my Older Sister get a nutritionist's license instead of becoming a chef. Seriously, this is kind of serious."
*****
The dining table, which would normally be filled with convenience store lunches, was now lined with warm, homemade dishes prepared by Ryosuke.
They were all quick, simple dishes, and the rice was instant, bought by Ryosuke. Even so, Manaka's tongue and stomach were overjoyed by the familiar flavors.
It's frustrating, but spending time with Ryosuke really is fun.
As usual, Ryosuke talked a lot—about his school, about his younger sister Marin's recent activities.
More than anything, he was a good listener. He drew out Manaka's complaints about her new job and laughed at the silly stories from their cohabiting life.
Before I knew it, I'd relaxed and let my guard down.
This is bad. This won't do...
Even as the thought crossed her mind, Manaka found herself rationalizing: If we just interact as ordinary siblings, there shouldn't be any problem, right?
That's when she suddenly noticed Ryosuke's bags.
"Did you go shopping?"
"Yeah. I was buying shoes."
"With your new girlfriend?"
"No, just with a friend."
"I see..."
She couldn't bring herself to ask more. As a sister, she couldn't tell what the normal boundaries were anymore.
How am I supposed to act like his sister now...?
The time spent with Ryosuke passed in a flash. Her ever-polite younger brother-in-law swiftly finished clearing the dishes.
"Well, I'm heading out soon."
With a simple farewell, he headed toward the entrance.
"I see..."
Don't dwell on the past, Manaka warned herself, following her grown-up younger brother-in-law to the door.
"Older Sister, I'm seriously worried you won't starve to death while Ryosuke is away."
"I won't!"
"You might get malnourished, or worse, gain too much weight."
"I won't! Besides, he'll be back in a week."
"Right."
His smile remained as inscrutable as ever. But seeing him relaxed, even a little childlike, made it impossible for her to hate him completely.
Then—
"Older Sister."
Caught off guard.
His left arm grabbed hers, pulling her close.
"Ah..."
The moment she gasped, their lips met.
Ryosuke was standing on the lower step, putting on his shoes, so their faces were at nearly the same height.
"Mmm... N-no... Ryosuke—! Stop it... Nngh..."
Though he had grabbed her arm, it was only one arm, and his grip wasn't particularly forceful.
Even though she could have easily shaken him off if she'd really tried, Manaka didn't.
Whether it was conscious or unconscious, even she didn't know—but she was certain that her reason was yielding to instinct.
Ryosuke's lips, which she'd experienced countless times before.
His tongue, gentle yet insistent. His breath. His body heat.
All of it paralyzed Manaka from the core, stealing her calm and rational thoughts.
No... This is wrong... I shouldn't...
Behind her eyes, the smile of her beloved fiancé surfaced.
They'd grown up practically as childhood sweethearts, their relationship blossoming naturally in middle school, attending the same high school—and they'd always believed, without a doubt, in a happy future together. In fact, that future was unfolding before her very eyes.
The only miscalculation was that Manaka had ever met Ryosuke.
What made it worse was that I ended up living with him as family, closer to him than anyone else, with no escape in sight.
"Ah... mm... mmm... haa... mm..."
I knew exactly how his lips would move next, how his tongue would enter me. Even after so much time had passed, my body still remembered him so well from all those times our skin had touched.
After all, I finally left home...
I wanted to end this relationship, but I was terrified that my fiancée would find out about my connection with Ryosuke. So I selfishly insisted on moving in together.
And it was actually working.
Little by little, I thought I was forgetting Ryosuke's body heat, that I could finally focus solely on my fiancée.
But that hope was shattered in an instant.
I'm sorry... I'm so sorry...
In her mind, Manaka apologized to her fiancé over and over, yet at the same time, she was drowning in the sweet pleasure of the kiss.
She felt no dissatisfaction with her fiancé whatsoever.
He was dependable, accepting her flaws, and generously kind to others. He was diligent in his work and beloved by everyone—a man couldn't be any more wonderful.
And yet, here she was.
Three years ago, she had yielded to Ryosuke, who was still shorter than her at the time, when he pressed himself against her and demanded her so fiercely. Since then, Manaka had been betraying her childhood sweetheart, her fiancé, over and over.
Aah, I shouldn't, I can't, I don't want to...
She felt the firmness of Ryosuke's fingers against her forearm. Then, when she tried to push him away, her hand was stopped against his chest, forcing her to acknowledge his physical growth.
And then, the sweet pleasure she had been enduring for so long, the kind she had always suppressed, was flooding into her mouth as if to say, How about this?
"Older Sister—"
"Mmm... Mmm. Haa... Ryosuke, mm... Mmm..."
At some point, Manaka had begun seeking out Ryosuke's lips herself. No, that phrasing was too vague.
In truth, overwhelmed by the intense pleasure and wanting to make Ryosuke feel even better, she had returned the affection of her own volition.
A long, lingering kiss.
A sinful, lewd mouth-to-mouth caress—something she'd never experienced with her fiancé. Manaka's rationality melted away, swept away by the sensation.
"Ah... Mmm... Ryosuke?"
Ryosuke suddenly broke the kiss and said, "I'm glad I could see my Older Sister looking so lively today."
He released her wrists, freeing her.
He left with an almost heartbreakingly simple farewell.
Manaka had no reason—no righteous cause—to stop him.
"See you later. I'll be back."
"U-um... yeah."
After watching my younger brother-in-law walk away, I was consumed by intense guilt.
What kind of "yeah" was that? How could I possibly promise to see him again?
I... did it again...
I surrendered to pleasure, letting it wash over me.
I've experienced this awful feeling far too many times before.
The day I first touched skin with Ryosuke.
The day I, thinking of my boyfriend, allowed myself to be seduced by my younger brother-in-law's affection, feeling so good, so good I couldn't stop.
Since then, I've invited Ryosuke into my room, taken the initiative to ask him—
Making up flimsy excuses like "Could you tie my hair?" to be alone with him, to press our lips together, to undress each other, to exchange fluids, to climax fiercely together.
And each time, the overwhelming wave of regret that followed.
Ah... aah...
Manaka's body suddenly remembered how everything had brought her exquisite pleasure.
If Ryosuke had kept asking me like that... If he had pressed me against the wall and pinned me down...
In the apartment she shared with her fiancé, Manaka would have taken him in. She would have savored that wonderful sex over and over, begging him, clinging to him.
She would have brought Ryosuke to the bed where she and her fiancé slept, and they would have rocked together again and again.
I... I... I'm sorry, I'm sorry...
She hugged her feverish body and curled up in the hallway.
Tears streaming down her face, she glanced back at the living room. She had lived here with the man she loved for over a year, yet all she could see now was Ryosuke.
The dining table where they had just shared a meal. His figure in the kitchen. His gentle voice calling her name. The warmth of his palm. His lips. His voice—
Everything's ruined now.
All my patience. All my resolve.
It was all for nothing. Crumbling into dust.
(Ah... Ahh...)
I can never confess to Ryosuke.
I'll have to live with this guilt forever.
The thought...
"Ugh... Ugh...!"
A searing ache burns deep in my gut.
Filthy desire slicks my soft flesh, searing it relentlessly.
"Haa... Haa...!!"
This hell will surely never end.
Even after marriage, always. Forever, forever.
(Ryosuke... Ryosuke...)
As Manaka dwells on this forbidden relationship, she writhes violently.
Whether it's from terror or ecstasy, even she can't tell.