That summer, Manaka was constantly in Ryosuke's arms.
Her daily life remained unchanged. Since she was planning to advance to university through recommendation, her studies required only moderate effort, and with club activities finished, she had plenty of free time.
She spent time with friends and went on dates with Takuma. Her time with her boyfriend was intense. The boy who had once been merely a childhood friend was growing into a mature man, treating Manaka with great care.
Her parents seemed to be spending less time together as a couple. They were both busy with work and social engagements. Still, the family of five occasionally gathered around the dining table. The conversation with her parents was unremarkable, her younger sister had become somewhat more sociable, and then—
"Nee-san, you want seconds, right?"
"Ah—"
Ryosuke stood up from his dining chair and, without waiting for a response, took Manaka's bowl to serve her more rice.
"Haha. It's really great that Manaka-chan and the others come to our house."
My stepfather, unaware of the situation, spoke with conviction.
"Having a sibling really does change you, doesn't it?"
In the kitchen, Ryosuke shrugged without meeting his gaze. To his father, however, this was progress enough from his "rebellious son." The fact that his son was now eating with the family and smiling in a cheerful manner.
Yet it seemed his father's relief stemmed more from the fact that Ryosuke was finally ready to leave his protective grasp than anything else.
Manaka was beginning to see this as well. Though Ryosuke showed no outward signs of it, when she pieced together the stories he told about his father, she couldn't help but see it that way.
But... is that really true?
Perhaps it was only Ryosuke's subjective perception. No matter how perceptive he was, did he really have the ability to see through people that deeply?
"Here you go."
Ryosuke, now fully embodying the role of "little brother clinging to his older sister," flashed a practiced smile.
What a shameless face...!
Every night, only Manaka knows what he's doing here. And she doesn't want anyone else to find out.
She lowers her gaze to the bowl in front of her. Manaka has a voracious appetite, and even in this situation, she's hungry. The white rice... frustratingly, it's exactly what she needs to satisfy her hunger.
*****
"So, who do you think I ran into?" Takuma asks during their daily phone call.
No matter how much they talk during the day, their conversations never run dry. They're on the same wavelength. Even the most trivial chatter never bores them; it's just comfortable.
"Who?"
"Hasegawa. Remember him?"
"Ah, from Same Elementary School? He transferred, right?"
"Yeah, apparently he's planning to apply to the university here."
"Really? Well, we'll have to get him in trouble again."
"Right? Ugh, I should probably start studying, though."
"Yeah, you're right. We don't have time for this."
"Hey... so, can you help me with my assignment tomorrow?"
"Sure, but you'll just fall asleep halfway through, won't you?"
"No, tomorrow for sure! I'm reborn today!"
"Stop saying that—"
Knock, knock.
The sound from the door interrupted their growing excitement.
"..."
"What's wrong?"
"...It seems like Marin (...) is calling."
"Ah, go ahead and answer. But you know how much Marin-chan really adores her 'big sister,' right?"
"Yeah, I guess."
"Be nice to her, okay? See you later."
"Right..."
After ending the call and placing her phone on her desk, Manaka's heart was pounding so fast it felt like it might burst.
Even Takuma had been lied to.
It wasn't Marin calling at all.
Approaching the door, she hesitated, her feet stopping just short.
She knew exactly who was on the other side. Since that day, he had never forced himself on her again. He only reached out when she responded to his subtle invitations. He followed those rules with infuriating diligence.
The door wasn't locked, but he never entered without her permission.
Therefore...
All I need to do is not open the door.
Just that simple action would let me escape him. It's very simple. It's very easy.
Why...?
The latch bolt clicked. Before I knew it, my right hand was gripping the lever handle and turning it down.
Ryosuke was standing in the hallway. He's a beautiful boy, terrifyingly so. Moreover, he's beginning to exude a masculine aura, a fierce virility.
If I were bewitched by him—no one could escape.
That must be true.
If it isn't... I'd be a fool.
To interrupt a conversation with her lover just to invite her younger brother into her bedroom for defilement...
*****
My older sister-in-law's body always teaches me the pleasures of sex down to its very core.
When Ryosuke entered the room and looked at her, she averted her gaze, her cheeks flushing crimson as she shrank into herself. She was tense, but when I embraced her, she felt so soft, and she smelled so sweet.
"N-no...!"
Her voice was thin and weak, completely different from the cheerful tone she used when talking to others or the relaxed voice she had when at ease. Even she must realize this feeble protest wouldn't be taken seriously.
When I kissed the back of her neck, I felt it was clammy with sweat. Her collarbones were delicately shaped, her shoulders slender. It was strange—she seemed so fragile, yet I sensed a surprising strength within her.
"H-ah...mm...!"
Even the slightest teasing touch made Manaka writhe and moan seductively.
"Nee-san. Take that off."
"..."
I could feel her tension rising. I released the embrace and took a step back. She retreated to the edge of the bed and removed her T-shirt. Her gray night bra, stretched to the limit, seemed soaked with sweat and pheromones.
"Take that off too."
"..."
Manaka glared at me resentfully before hooking her fingers under the shoulder straps of her bra and pulling them down simultaneously. With a soft swish, her firm breasts were revealed.
"Is this what you want? Now, hurry up!"
"May I touch them?"
As I spoke, Manaka's nipples, which she made no effort to conceal, trembled visibly.
"I just want you to finish quickly!"
"Do you say that to Nii-san too?"
"O-of course not! Takuma and I—"
"You take your time to love each other?"
"..."
I leaned closer, tracing the rounded contours of her breasts with my fingers.
"Ah! Nngh—! Ah, ah—! I told you to touch me already—! Nngh—!"
No matter how harshly she spoke, a gentle stroke of her nipples made her shudder. When I pinched them, she clenched her teeth, trying to endure the pleasure.
"Ugh... Uuu... Nngh... Ugh—! F, uuu—!"
My sister's erogenous zones are easy to find. All I had to do was tease her a little, and she quickly reached her limit.
"H-let go... I'll do it..."
Perhaps unwilling to remain on the defensive any longer, she clung to Ryosuke's waist and pulled down her nightgown.
"Take off your underwear."
Her glare dared him to protest, but her eyes quickly shifted to his lower abdomen.
"...mm, ugh...nn"
Her thick lips latched onto his penis through his underwear. The shaft was engulfed, the glans slickened by her tongue.
"Mmm, leh, u, mmm..."
"You've gotten better at this, haven't you? Did you practice on Nii-san too?"
Another glare.
Ryosuke had taught Manaka fellatio, if her confession was to be believed. But recalling her initial clumsiness and hesitation, it must have been true.
"Fuu... mmm, uhh..."
But after a few attempts, Manaka had improved with practice.
With smooth, practiced movements, she completely removed my underwear. Then, her glistening tongue eagerly attacked my exposed penis. The sensation was warm and slightly moist. From my testicles to my shaft, from the glans to the head, my entire penis was slick with my older sister-in-law's saliva.
"Mmm, pfft, nroh... juru... juro..."
Despite my initial resistance, her passionate blowjob now felt almost tender.
She took me deep into her mouth, sucking vigorously and stroking me with her lips.
"You couldn't show your parents this, could you?"
Just moments ago, we were cheerfully sharing a meal at the dining table. Our parents downstairs, relaxing, couldn't possibly imagine their sister and brother were indulging in such acts.
"Mmph, mmm, fuh, juru—"
Manaka kept her head bobbing up and down relentlessly, as if determined not to hear my words. If she were to let me cum in her mouth now, it would feel amazing. But for now—
"Thank you. I'll do it for Nee-san too."
It's crucial to maintain control.
"I'll do it with my fingers—turn your ass toward me."
Manaka, still silent, parted her lips with a lingering reluctance, as if reluctant to let go. She turned to face the wall on all fours, thrusting her shorts-clad lower body toward me.
So obedient...
She seems unable to refuse when given an order.
Sliding her shorts halfway down, I slipped my right hand into the lush valley of her buttocks. Her woman's hips were damp with arousal. Amidst the soft, sticky flesh, I found small, grainy protrusions.
"Ah?! Ah, u, u, ah—!"
"You like your clitoris, don't you?"
Just rubbing the skin above it with my finger made Manaka's hips twitch, then twitch again. Collecting the love juice dripping from her folds, I carefully peeled back the hood and gently pinched the clitoris between my index and middle fingers.
"Yah?! Nk, fuuuuh?! Ugh, ugh—"
What must she be feeling, showing her vulnerable rear and being teased with a single fingertip by her younger brother? Just imagining it makes me aroused.
My sweat and love juice secretion has worsened. If I keep this up for another minute or two, my right hand will start to soften.
"I'm going to touch Nee-san's favorite spot."
When his middle finger found her entrance, Manaka shuddered violently.
"Is that okay?"
"D-Don't ask... Just do it if you want to—Ngh...!"
"Of course I want to. This hole is so lewd... All slick and dripping, burning hot."
He could have easily slipped his finger in with a smooth motion, but her walls clamped down tightly around it. Just a single finger, yet her insides were so pliant he didn't even need to acclimate her. Her folds were thick and soft.
When he vigorously rubbed her with his finger,
"Mmm... Huh... Hnnngh... Ah... Aaaaah!"
"Keep it down. We have neighbors, you know."
His words were taunting.
His fingers were probing.
"Ngh... Oh... Nnngh...!"
Manaka, face pressed into the bed, desperately tried to endure.
He curled his fingers inside her, rubbing them against her walls with his palm. Love juice splattered from her slick folds, soaking the sheets and floor.
Manaka, on all fours, could no longer suppress her spasming body.
"Niih... Oh... Ahh..."
"Haha, Nee-san, you're just too easy."
Ryosuke himself was amazed by this talent—how effortlessly he could pinpoint her vulnerabilities. He knew exactly how to stroke her inner walls to make her body sing, and what words to whisper to make her burn.
Originally, he'd developed this skill to avoid causing waves in daily life—or perhaps it was innate.
"It's okay to come—really come, not just tease. You can let your brother's fingers make you really climax."
With the last shred of her rationality, Manaka shook her head vigorously, but she had long since reached her limit. Her back arched dramatically as she climaxed, her lower body contracting and her vaginal muscles clenching tightly.
Ryosuke pulled his middle finger out as if he were devouring her, then pressed his glans against her entrance and thrust in.
"–Ngh?! W-wait, I'm coming! I'm still coming! Nguu, Nuuuuu!"
He grabbed her hips, pulling her closer as his penis scraped against her inner walls.
As Manaka writhed between post-orgasmic spasms and new waves of pleasure, Ryosuke methodically violated her. He had just learned, with his fingers, exactly where to press to give her sexual pleasure.
Still restraining her plump buttocks, Ryosuke withdrew his hips, deliberately stroking her vaginal walls with his penis.
"T-there—?!"
"Here? Does that feel good?"
"~~~~~! I-I don't know! Don't know that spot! You're hitting it—!"
I confessed that Takuma had never scolded me before.
The way her slick, glistening lips enveloped me, the exposed junction between us... it was a visual pleasure in itself.
The sticky wet sounds, the scent of a woman.
Above all, the sensation of my older sister-in-law's warm, clinging pussy wrapped around my cock. Inside her, her body writhed with pleasure, her inner muscles clenching passionately around me.
"Think of me as your brother and feel as much pleasure as you want."
"How can I...? Nngh, nn, nnnuu...!"
When I relentlessly teased her weak spot at the same pace, Manaka climaxed over and over, almost comically.
I want to fill this bitch with my seed.
The newly awakened primal urge screamed at him, but Ryosuke resisted the temptation to ejaculate with ironclad willpower. Not yet. I want to stay connected to this delightful hole for longer... More importantly, I want to take Manaka even higher.
"I'll make you feel even better than Nii-san ever could."
This time, I thrust deeper. The indescribable pleasure of my rigid shaft being enveloped by her slick flesh from base to tip was unparalleled.
Manaka's body arched sharply—her primal instincts must have been intensely stimulated as well. No words were needed; the connection between our joined bodies conveyed it all.
"Inside... no... ah... ah... ahh... you're reaching it... you're reaching it! Ugh... uuuuuu...!"
We collided with bestial desire, climbing together toward the peak.
My hips ground against her soft buttocks, driving my release deep into her core. The spasms in my lower body wouldn't stop from the overwhelming pleasure.
"Nee-san..."
"I'm... aahh?! Ugh... nnnngh...?!"
After our violent climax, I collapsed on top of Manaka's limp body. Still connected, our heated bodies felt as if they were melting together, the sensation utterly blissful.