My Little Sister Is the Best F*p Material

Volume 9 Chapter 04: What I Love About Onii-chan

“Nn… Onii-chan’s room…”

Miyu woke up on my bed, rubbing sleepy eyes as she sat up. Even weak from waking, she instantly recognized my room, a sign she’s grown used to spending time here. Our sibling bond has settled—especially with her strong desire to love as siblings—and while it’s a subtle shift in our lover’s dynamic, it’s quietly heartwarming.

“Morning. Rested?”

“Yeah… um, it’s still night, right? Why was I asleep…?”

She curiously eyed the T-shirt and sweatpants I’d put on her. Sleeping in her dress would’ve wrinkled it and been uncomfortable, so I changed her and cleaned her up a bit. I couldn’t quite scoop out the cum deep inside, though.

“Oh… right! I had a promise with you, sorry! I’ll shower quick…!”

“No rush, take your time.”

It was past 10 p.m. The promise lasted until midnight, so time felt a bit wasted, but we’d had our fun, and she was exhausted. Her begging for creampies in that goth-loli outfit was so hot, I’d mostly spent myself anyway.

So, I figured we’d enjoy the remaining time differently—but true to her sense of duty, Miyu couldn’t let it slide. She bolted out to wash up. While she slept, I’d eaten, bathed, and surfed the net to kill time, occasionally gazing at her sleeping face, making time fly.

“Sorry for the wait. Took a while… your stuff… wouldn’t stop dripping…”

She hurried back, but by the time we settled, it was past 11 p.m. Washing off makeup, skincare, drying her hair, and cleaning out her cum-filled vagina took time—no complaints there.

“Want food? There’s jelly or salad.”

“I’m fine. Your creampies filled me up.”

Her stomach and womb are connected now? Not surprising for this sister.

“What about you? Less than an hour left for the promise.”

“I’m pretty satisfied with the sex. But since we’ve got time, I’ll make use of it.”

“Go for it!”

Surprisingly, she was enthusiastic. She must want to make the most of this chance. Getting licked, cosplaying, and creampied—she likely expected all that when she gave me the ticket. She’s enjoying this too.

Fresh from the bath, she’s in my clothes, sans underwear. Prim as she seems, she loves cliché boyfriend shirts. Her quirks show up in subtle ways. Like now, instead of sitting on the bed’s edge, she kneels on the floor to keep her head lower than mine. Outside, she trails half a step behind me. Being submissive to her beloved feels right to her.

“Then, one more order. Answer honestly, okay?”

“Honesty as an order?”

“Exactly.”

I wasn’t planning more sex right after she woke. But if she woke before midnight, I had something I wanted to ask, even if I had to order it.

“Miyu, do you love me?”

She blinked her big eyes, confused by the question.

“Can I ask why you’re asking?”

“In the bathroom, during sex or licking, you said ‘hate’ and ‘love’ a lot… I wondered what your true feelings were…”

“Ah, got it.”

She thought for a moment, stood, signaled me to move from the chair to the bed, and grabbed a loose-leaf notebook from my desk. She wrote something, flipped a page, drew a circle, sat cross-legged in front of me, and showed it.

“Hm? A circle? Like an ‘okay’ sign for love?”

Why not just say it? I’m used to her quirks, but this cryptic move puzzled me. As I stared, she added a vertical line through the circle without explanation.

“Uh… what… not a weather symbol… so, does it mean hate?”

As I grew anxious, she shaded the left half with diagonal lines, drew an arrow, and wrote at its base.

‘Hopeless siscon’

A straight-up insult.

“Sorry, okay? But I can’t help it. My body’s wired to lose control with you. As lovers now, isn’t that a good thing…?”

She once said she can only love one person her whole life and would die if abandoned. She was anxious when I was with Yuka or Yamamoto-san, but now that it’s resolved, she’s committed to our love. My hopeless siscon nature should be ideal for her.

As I mulled this, she drew a horizontal line, splitting the unshaded half, then crosshatched the lower quarter, adding another arrow with new text.

‘Always thinking about sex’

Each comment made me feel guiltier. I want to cherish her as a girl, but my amplified summer lust is uncontainable, and I can’t vent it on other girls. She made me this insatiable, so as my lover, she has to take responsibility.

I’m sorry but have no plans to change. Her body will handle my daily lust—our most critical sibling decision.

She halved the remaining quarter, roughly shaded the bottom, and added a third arrow.

‘His play requests are just gross’

That hit hard. Undeniable. Begging to lick her pussy so persistently—can’t argue with that.

“Uh, Miyu? There’s only an eighth left for my good points…”

Whether complaints or boyfriend reviews, she stretched a final arrow from the last eighth and wrote a fourth comment.

‘All sorts of Onii-chan things’

So vague…

“Look, I know I went overboard. As lovers, I want to talk about our future…”

I’d considered cutting sex to every other day. But since she loves my heavy loads, I’ve done it daily for her sake. Still, hearing it so bluntly, maybe I should rethink controlling my lust.

As I reflected, she flipped back a page, shyly hiding her face, and showed her first note.

‘What I love about Onii-chan’

Our eyes met, her face half-hidden, and the unexpected confession made my heart race.

I was just getting roasted, wasn’t I? I leaned closer, flipped the page, and saw the same complaints.

“So… you love me?”

Repeating my question, she finally spoke, blushing with softened eyes.

“I love Onii-chan so much. There’s no other answer.”

Her straightforward love made my body heat up, cheeks burning. After all that anxiety, her genuine feelings hit hard. I’m too loved by this cute sister.

“The hopeless siscon part, fine, it’s mutual love… but always thinking about sex and gross play requests—that’s just straight-up criticism, right?”

“Well…”

Clearing her throat to compose her flushed expression, she continued.

“Handling your sex drive is tough, but imagining life without it feels lonely, so I see it as a good thing… Also, um… I want it too…”

The last part’s her real answer. Lucky to have a sex-loving sister.

“And the next one?”

“Your gross play requests are genuinely gross, so that’s the honest truth.”

Yeah, figured. I knew it.

“But sex with you is fun, and I’d never ask for those plays myself, so I’m grateful too.”

“You know, it’s okay if you ask me for sex sometimes, Miyu.”

“Well… I mean… I’m thinking about it…”

Miyu’s voice softens with a hint of embarrassment. She’s trying to be honest about her desires, which I appreciate. I’m not in a rush or trying to push her.

“So, I can just ask you for any kinky stuff I want, right?”

“No, impossible things are off-limits. If it’s something you absolutely need for your one-and-only life, ask Kanade-san.”

What a comeback. Shouldn’t it be, “Anything you desire, please ask”?

“What do you take Yamamoto-san for…?”

“A kinky play specialist?”

“That’s harsh!”

“She said so herself, okay? I respect Kanade-san as a person.”

She hurriedly adds, mentioning she has proof in their messages. Well, there’s probably no kinky play Yamamoto-san wouldn’t do.

By the way, Miyu still keeps in close contact with Yamamoto-san, apparently sneaking around behind her lover’s back. What are they talking about? Not cheating, right? I wouldn’t mind if it’s with Yamamoto-san, though.

“Anyway, I get that you love me.”

“I adore you.”

She says it smoothly, her expression smug. Shy Miyu is great, but this confident, almost wifely sister whispering love is charming in its own way.

“The ‘Onii-chan things’ part was a bit complicated, though.”

“That’s tricky for me too.”

She puts the loose-leaf back on the desk and sits beside me.

“It’s hard to pinpoint what I love. Like, right now, we’re totally flirting, right?”

“No doubt about it.”

No matter what anyone says, this is our sibling flirting. Perfect distance, perfect banter, filling in each other’s feelings as inexperienced lovers, confirming our love.

“Your responses when we’re like this feel just right. Being with you is easy and fun. Honestly, that’s so attractive, everything else is just a bonus.”

Then, in a whisper, she adds, “The sex stuff is separate, though.”

“So, it’s hard to put into words, but I’m always thinking I love you.”

Her voice is clear. This flirty exchange has loosened her heart, lips, and cheeks. Even if others don’t get it, we’re steadily nurturing our love.

“Can’t you at least say ‘love’ more?”

“It’s embarrassing…”

“If that’s the case…”

Unless she’s in full-on erotic mode like during those massive creampies, getting her to say “I love Onii-chan” and kiss me is tough. She knows as a lover she should express affection more, but her cool persona makes it hard, and I get that.

“I want you to say you love me more. For the remaining time, that’s my order… okay?”

She tilts her head curiously at my near-pleading command.

“You’re okay with me saying ‘love’ because of an order?”

“Yeah. It lets you think, ‘I’m only doing it because I have to,’ right?”

“I guess so.”

She stares at me.

“Okay, I’ll say it… I love you.”

“Good start.”

“I love you, Onii-chan.”

“I love you too, Miyu.”

We lock eyes, sharing our feelings. My own voice echoes in my head, making me shy. But this isn’t enough to close the emotional gap.

“Kiss me too.”

“Fine, fine.”

Her “can’t be helped” look isn’t reluctant this time—it’s encouraging, like, “Finally getting into it, huh?”

“I love you, Onii-chan.”

She cups my cheeks and softly kisses my lips.

“More.”

“…Okay.”

Bound by duty to obey, she agrees instantly.

“Nn… chu… haa… Onii-chan, I love you. Always will.”

“I love you too, Miyu. Forever.”

Kissing, gazing, confessing, we kiss again to confirm our feelings.

“Miyu, more.”

“Nfu. How many times?”

“Until midnight. Over and over.”

“Got it. I’ll obey.”

She hugs me, kisses me, pushes me onto the bed, and tangles her tongue deep.

“I love you, Onii-chan… nn… haa… chu… nn… love you… Onii-chan… love… nmu… haa…”

Not an endless kiss, but short ones, gazing in between, whispering love instead of catching breath. Our passion intertwines, far more lover-like than joining genitals.

“Nn… chu… Miyu… I love you… ah.”

I didn’t mean to notice, but I saw it and couldn’t help it. Feeling my mood shift, Miyu stops kissing.

“Hm? What’s wrong?”

“Uh, just… the time…”

Glancing at the wall clock, I realized it’s nearly midnight, the deadline for her to obey my orders. Her saying “love” is because of my command, and its power fades after midnight. We could’ve stayed in our lovey-dovey world if I hadn’t noticed, but promises matter to us, so this interruption was inevitable.

“Why’d you notice?”

“Sorry, it caught my eye.”

She’s annoyed I noticed, clearly enjoying our exchange.

“Take the clock down, Onii-chan.”

I remove the wall clock and hand it to her. She checks the back, disables the satellite sync, turns the minute hand back a full rotation, and hands it back.

“The clock seemed broken, so I fixed it.”

I can return to our flirty time.

I’m thrilled.

But this feels like we’re stuck in our early days.

“Miyu, it’s not wrong.”

I check the time on my phone, set the clock precisely, rehang it, and return to the bed.

“…No more?”

She looks up anxiously. I want to keep going—her rational “love” and kisses are a rare bliss. But it’s only because of my absolute order. Even if it’s her true feelings, that’s the situation. As lovers now, I feel we can do this without a vow.

“Miyu, say you love me and kiss me again.”

Midnight passes. She notices too.

She looks away, clenches her fists at her chest, but doesn’t deny me instantly. I know she loves me. She just needs to get used to saying it.

She could’ve kept going with momentum, blaming me if midnight passed mid-act. But she knows the promise’s effect is gone, so she can’t.

“I love you, Miyu. As a girl and as my sister.”

I confess first, cupping her cheek, and kiss her lips with all my courage. When I pull back, she smiles, shy but happy.

“I love you too, Onii-chan. As my brother and as a man. So…”

Nn—soft lips touch, breath escapes. Our kiss doesn’t break.

“Onii-chan… I love you… I want to kiss you more… lots… nchu… chu, puchu… pero… amu… nn, nnn… haa… love you…”

“Miyu… nn… I love you… Miyu…”

Too eager to move to the bed, we explore each other’s mouths, sucking tongues. Her saliva replaces my cum, and I lick deep inside, savoring her trembling reactions. For us, rarely kissing even as lovers, sibling kisses feel far more taboo than sex.

Sex can be compartmentalized as pleasure. A one-sided kiss could be part of play. But clinging desperately, tongues entwined while gasping, proves we’re brother and sister yet man and woman.

Kissing will always be our way to confirm love as siblings—using that bond to indulge in depraved pleasure, a taboo act of affection.

It fuels my lust, amplifying my semen. My erect cock soon presses against her stomach.

“Nn… mu… haa… nnn… ah… M-Miyu… sorry, I want to cum again…”

“Nn… nn… really… after all that in my vagina, you still want more…?”

Her scolding comes with a sloppy smile. My erection shows my arousal, but her panties must be soaked with her juices.

“You’re so horny for your real sister.”

“Sorry. I thought I was spent, but your kisses make it impossible to hold back.”

“Hmm, really? Hehe.”

Miyu hugged me tightly, then kissed me with a fierce intensity.

“Chuu… hamuchu… juru… puhaa… But I love this Onii-chan too.”

She happily stroked my erect cock. My insatiable lust is a part of me she finds appealing—after all, she’s the one who made me this way.

“I don’t know if I can cum, but can I put it in?”

I slid my fingers along her crotch. Even through her culottes, I could feel her wetness.

“Today’s special, so I’ll put it in for you.”

Laid on the floor, I watched her straddle me, shedding her lower clothes. To think she’d take the lead like this—I couldn’t have imagined it when she first drank my cum.

She pulled down my pants, using my erect cock to pry open her tight hole. Her narrow vaginal entrance stretched as my thickened tip forced its way in. With the rod’s hardness and ample lubrication, it slid deep quickly.

“Aah… ah… aaah…!! O-Onii-chan’s… big one… it’s going in…!!”

Grimacing yet smiling, she moved her hips up and down. Her clumsy, unpracticed cowgirl motions were endearing.

At first, she eagerly rubbed my cock with her vaginal walls, mimicking porn by getting on all fours, swaying her hips to milk me. But after thirty seconds, like a premature guy, she slowed to single strokes, pausing between.

“Fua… haa… with Onii-chan’s… I want to grind deep…”

Her pleasure zone isn’t her G-spot but her cervix. Pounding without touching it is torturous teasing for her. She’s trying for me, but her mind must be screaming to lower her hips and hit that deep spot.

“You can grind deep. Just keep moving your hips, please. I want to cum too.”

“U-Uh… okay…”

Taking my permission as a command, she braced her palms on the floor and lowered her hips until my cock’s base was inside.

“Ugyu… u… aaah… h-hard… so big…!! Nn, nnn, ah, ahyugohi… deep… grinding… u…!!”

Instead of big motions, she switched to pressing my cock against her cervix. Her wet nature makes sex noisy, usually embarrassing her, but now she’s making lewd sounds herself.

She’s slowly letting me see her erotic side. Her taking the lead in cowgirl is a miracle. Resisting the urge to thrust, I surrendered to her awkward rhythm, heart trembling.

“Haa… hyugoi… nn, ah, ah, no…!! Fuu…!! Aah… u, moving myself… I’m… cumming… u, aaah, ah, aah…!!”

Moaning as she moved, her speech slurred within minutes. Each climax tightened her vagina, pausing her motions to let spasms subside, but pulling out scraped her walls, triggering more orgasms.

Exhausted, her legs gave out, hips crashing down with a wet guju, making her cum again. Near tears from failing to stroke me properly, she pushed her body to keep going.

“Sorry… Onii-chan… u, ugu… I’m… the only one cumming… can’t anymore… can’t make you… sorry…”

Drained from climaxing, she couldn’t move. She was so cute, tight, and fuckable, but more than selfish urges, I wanted to be there for my sister, honest about sex.

“Thanks, Miyu. I’m close. Just a bit more to make me cum.”

When I pleaded, she murmured, “U… okay…” and forced her exhausted body to move.

“Moving’s tough now, right? Can you… kiss me instead? That’ll probably do it.”

“Kiss…? That’s okay? Hehe, I can do that forever.”

She collapsed onto me, arms around my neck, tongue diving in. Each brush of her mouth made her cum again, her grip tightening, making breathing hard. Feeling her love, her saliva fueled my cock’s swelling, craving release.

I was close. Each twitch of my cock stretched her tight vagina, her moans like screams stoking my lust. Precum leaked as her relentless climaxes synced with my impending release.

“Aaah, aah, nguuaah…!! Aanah… Onii-chan…!! C-Cumming… cumming… nn, uu, naaah… it won’t stop…!!”

Unable to keep kissing, I hugged her head, thrusting my tongue in, stirring her mouth with primal lust. Byukubyuku, byuku—!! I poured cum inside.

Her final intense orgasm from my ejaculation made her collapse, fainting. I tried to catch her, but my body, drained from forcing one last cum, wouldn’t move. Hitting my head on the floor, I blacked out into a dream world.

I woke when dream sex with Miyu triggered a wet dream.

“Ah… shit…!!”

My pulsing cock spilled into her vagina, still connected as we slept naked from the waist down. Her body acted like a condom, saving the floor, but sleeping like this all night? Sweat and AC left us chilled.

“Nn… fa… u…”

Waking from the creampie, Miyu sluggishly sat up, rubbing her stomach filled twice—night and morning.

“I can feel your sperm swimming.”

“You can actually feel it?”

“Not right after waking.”

If it’s not right after waking, you can feel the movement of the cum inside you, huh?

“Sperm swim toward the egg for days, right? So, with you creampying me almost daily, there’s probably not a day my womb isn’t full of your sperm swimming around.”

“That’s kind of terrifying to hear…”

I’m in no position to talk after unloading so much, but seeing Miyu happily cradling her womb, I can’t tell her to stop. We’ll need to seriously discuss frequency someday. As students with free time, it’s fine now, but as busy college students or adults, we won’t have time for this.

“Nfufu.”

Suddenly, Miyu’s expression softened, and even the morning after, she was in high spirits.

“What’s up?”

“Getting creampied by you first thing in the morning? Best wake-up ever.”

She squeezed her arms around her perky-nippled breasts, blushing with a shy smile. To think my sister got this erotic in just one night.

“You really love me, huh?”

“Love you tons, Onii-chan. Mwah!”

She kissed me with a lovey-dovey grin. I said it half-jokingly, riding yesterday’s momentum, but she’s fully in “Onii-chan love” mode. It’s not just the creampie—something feels different.

“You’ve gotten pretty bold.”

“I’ve gotta make up for all the times I couldn’t say it. So, if you want me to say I love you, I’ll say it as much as you want.”

With a carefree “ehehe,” she hugged me, sticking out her tongue for a deep kiss. Something felt off, and the moment her sticky kiss landed, it clicked.

“Nn… Miyu…! Your mouth’s burning hot!”

The contrast with her chilled body made her mouth feel scalding.

“Must be my love for you.”

She kept grinning. Cute, but this can’t be ignored.

“First, put on some clothes. I’m checking your temperature.”

“I’m fine.”

“Just do it.”

Grumbling, she dressed, fetched a thin front-open hoodie and thermometer from her room. 37.5°C—mild for her naturally high body temp, but still no pushing it. Good thing it’s the weekend.

“Sorry I passed out too yesterday. Should’ve at least covered you with a blanket.”

“It’s no big deal. I can take care of myself.”

“Still, yesterday was intense, right? I need to be more responsible…”

“No, stop with that!”

She yanked her hoodie’s zipper in protest, avoiding closing it to hide her prominent breasts.

“Yesterday was so fun. Don’t make it a bad memory.”

Clinging to me, she’s right. Caring isn’t just apologizing.

“Got it. I’ll be more careful.”

“Yeah!”

Her smile bloomed brightly. The fever’s part of it, but yesterday made her this affectionate. We’re finally acting like lovers.

“I’ll grab something you can eat and some fever meds. Wait in your room.”

“Okay~”

She skipped back to her room, hand raised. Fevers are rare for her, so I didn’t expect a mild one to melt her rationality like this. This morning’s creampie helped, but her being this lovey-dovey outside of sex? I hope she stays this way after recovering, at least when we’re alone.

(Where’d I put the spare meds…?)

Downstairs in the living room, I rummaged through stacked cases by the TV. Leftover pharmacy meds should be here.

“Kou-chan, what’re you doing?”

Mom came out of the bedroom. It’s early for a weekend, so Dad’s still asleep.

“Miyu’s got a fever. Looking for fever meds.”

“Here, I’ve got them.”

She handed me a sheet of pills, but gripped them tightly when I tried to take them.

“Kou-chan.”

Her expression was exasperated, not angry.

“Do it more quietly.”

“Huh…? W-Wait, you heard us?”

Last night, caught up in lovey-dovey stuff with Miyu, I didn’t think to keep it down. That was bad.

“Did Dad notice?”

“I told him you were watching a loud weird video.”

“Good… What would he think about me and Miyu?”

“Who knows? He doesn’t seem to suspect anything. He’s always been hard to read, so you’ll have to tell him eventually.”

Mom’s basically ordering me to confess. I need to plan for the future.

“Also, keep the noise down. Your dad gets riled up, and it’s a hassle.”

She warned me, not entirely displeased. Helping their marriage is great, but…

“You’re still young, Mom. Isn’t it a good chance? I’ll keep the noise down.”

She pouted silently. She’s so like Miyu.

“You know, at this rate, you’ll get a second sister.”

I froze. Mom had me young, so she’s still in safe childbearing years. Another kid would be welcome, but another Miyu? A decade from now, my life would collapse.

“It’s your choice to have another kid, but maybe a boy this time?”

I forced a stiff smile, knowing gender’s not choosable. I know that.

“Maybe a boy. A cute one like Miyu would be nice.”

She smiled, hand on cheek. A boy as cute as Miyu? That’d cause its own problems.

“Anyway, I’ll be careful.”

I grabbed an energy drink from the fridge and fled to Miyu’s room. She was bundled in blankets, looking pained.

“Fever worse?”

“Dunno. Check it.”

She lifted her T-shirt, exposing sweaty skin. Kinda hot.

“38°C. Rest for now.”

“You okay?”

“So far.”

“Wow, you’ve gotten tough. So reliable.”

Sex with Miyu and Yamamoto-san has made my body stronger daily. My rampant lust is a hassle, but growing dependable as a man? Can’t beat that.

“I’m home today, so I’ll stay here unless it bugs you.”

“Thanks. Stay… and hold my hand until I sleep, if I get sleepy.”

She hugged me, leaning against the bed’s edge. After yesterday, I’m not worried about catching her cold.

“I’ll be here tomorrow too. Tell me if you need anything.”

“Tomorrow, the day after, and forever, right? I want to be with you every second. A day apart, and I’d die. Daily kisses from now on, okay? Promise.”

She squeezed my neck with her feverish breasts. No sex until she’s better, please.

“I know. Nothing comes before you. I’m always here.”

“Ehehe, yay. With you close, I can sleep easy… nn… fua… nnn…”

She asked for hand-holding, still wanting to sleep. I gently gripped her hands, gazing at her sleeping face.

What’ll happen when her fever’s gone? She’ll be more open, at least. I’ll savor it slowly. Starting Monday, I’ll head straight home after school, or she’ll get mad. Next weekend, I want a date with her. Maybe a trip somewhere. Thinking of the future, it’s all exciting.

Imagining that bright future, I stared at her long lashes, lost in my lover’s cuteness.