The Story of How Producing My Timid Older Sister Developed My Sexual Preferences

Chapter 011: The Ugly Desire I Thought I Had Locked Away

(Sister POV)

“Haa… haa… haa… haa…”

I burst into my room in a daze and stood in front of the full-length mirror that I rarely look at. My face reflected in the mirror was bright red.

Teru-kun saw so much of the face I hated so much… but he praised me a lot. Teru-kun is a good boy, so he wouldn’t lie. I want to believe that.

It had been so long since I saw Teru-kun’s face up close. He had become really handsome. His face was slimmer, his bones more defined — he had become an adult. But his eyes were the same as back then. He was still my Teru-kun.

His face was bright red as he whispered to me. It felt… almost like a confession of love.

My heart was pounding so violently it felt painful, as if my whole body was shaking.

I could remember every single word he said. I checked each part he praised in the mirror, one by one.

Nose, mouth, eyes, even my freckles. I carefully savored his words again and again.

…Is this really the same face I’ve known until yesterday? The face in the mirror gradually started to look different.

Even though it shouldn’t be possible, I couldn’t recall what my old face looked like… My head was getting confused.

『You’ll become a beautiful woman…』

Does Teru-kun really see me as beautiful? If that’s true… I’d be so happy I could die.

“And… he said he likes my scent too… I love his scent so much too.”

The faint scent of Teru-kun still clinging to my clothes. The last time we were that close — no, the last time we hugged — was so long ago, back when Teru-kun didn’t have this adult smell yet.

He was so strong. In the past, I was always the one hugging him. Being wrapped up by him was a first.

Another unforgettable, wonderful memory with him was added.

The ugly lump of flesh reflected in the mirror was still trembling with joy.

“To think I could be this happy all at once…”

It was almost scary.

My daily life has been so fulfilling lately. It’s all because Teru-kun started talking to me a lot more.

After he entered middle school, Teru-kun went through his rebellious phase. He never yelled at me, but he fought with Mom a lot. He was irritated every time he came home, and as the years passed, he came home later and later. His social circle changed too — boys stopped coming over, and he started bringing girls home instead.

By then, we barely talked anymore. But even that was fine with me.

As long as he was alive, as long as my beloved Teru-kun was healthy and doing well, that was enough.

No matter what Teru-kun did, it was okay. Even if he committed a crime, even if he hurt someone. I would always, always be on his side until the very end.

The big accident I caused.

After that, I stopped actively approaching Teru-kun.

I would listen to anything Teru-kun said. I would do anything if it was for his sake.

The meals he devoured so happily. Teru-kun growing bigger day by day from the food I made.

I didn’t mind that he left his clothes scattered. While deeply feeling his scent change into that of an adult, I washed them every day.

The faint voices of girls and the creaking of the bed coming from his room. At first it made me dizzy and I threw up in the toilet, but now I’m fine. It’s just practice for when Teru-kun finds a good wife in the future, has lots of children, and lives happily.

But I suppressed all my own desires. Wanting to hold his hand again. Wanting to go out with him. Wanting to talk with him. I forbade myself from all of it. Anything I wanted for myself, I treated as forbidden if it wasn’t good for Teru-kun.

The ugly desire that made Teru-kun unhappy was——

I took off the T-shirt Teru-kun gave me, then the baggy pants.

The ugly mass of flesh appeared in the mirror. Breasts swollen to the point of bursting. An unnaturally developed pelvis and thighs. The jiggling flesh of my ass with every movement.

It’s true that the inside shows on the outside.

——That desire was just as ugly and pig-like as this body.

But lately, Teru-kun has been talking to me a lot.

Ever since that night when he saw me naked.

He stared at me so intensely that I thought he had seen right through to my ugly heart, and I wanted to die.

But after that, we started talking much more.

I was so happy. I was embarrassed about the photos, but when he said he wanted even one picture of me, my heart raced. Getting the T-shirt that smelled like him. Being praised so much about my face. Everything felt so good it was like a dream.

He even praised this body and said it was erotic. That it looked sexually attractive to him. Even though it’s this ugly body. I believe that’s true too. But the reason it looks that way to him is… because Teru-kun has forgotten about that night… before the accident.

The face in the mirror was no longer red. It was deathly pale with empty eyes.

No. I can’t stay like this. We’re going out soon, and I don’t want everyone to worry.

I need to switch gears.

I recalled the hug with Teru-kun earlier, burning it deeply into my heart. His strong body. His manly scent. His body heat. I thought it was a dream. A pure white world where time and space lost meaning — a different world where I was connected with Teru-kun.

It must be serotonin. The happiness hormone spreading from my brain to the tips of my nerves. Just this was enough to give me the strength to endure the dreaded beauty salon and shopping.

The face in the mirror had returned to the bright red, embarrassed face from earlier.

——Huh? My underwear feels slightly cold. Don’t tell me I got so happy that I…

I hurriedly checked the crotch.

……Thick, transparent mucus was forming long strings.

The muscles in my face, which had been slack with pleasure just moments ago, snapped back into a blank expression.

All the things I had locked away for so many years, sealed so tightly… had leaked out so easily from just one hug.

How filthy. Have I still not reflected at all?

Disgusting disgusting disgusting disgusting disgusting disgusting disgusting

The underwear, covered in what looked like trails left by a swarm of slugs, was thrown violently into the trash bin.

That’s right — I have to make Teru-kun’s lunch.

I washed the hand that had touched my underwear over and over and over with soap. Then I disinfected it with sanitizer spray, put on nitrile gloves, and made Teru-kun’s sandwich.

Chapter 012: The Senior at My Part-Time Job

Since Mom and Sis went shopping together like a happy mother-daughter pair, I’m home alone right now.

After that, Sis came back wearing a long skirt that reached her ankles and a huge poncho-like tunic. Without making eye contact with me, she hurried into the kitchen and started moving around frantically, completely unlike her usual slow and relaxed self. It almost looked desperate.

When Mom finished getting ready and came out of her room, she gave Sis’s outfit a suspicious look, but she was in high spirits for her rare outing with her daughter and left energetically just a moment ago.

My phone vibrated.

「I made sandwiches.」 — a message from Sis.

Oh, so while Mom was getting ready, she quickly made lunch for me.

Even though Sis making meals for me is completely normal, today it felt different. A warm feeling slowly spread through my chest.

I replied with 「Thank you.」

When I went to the kitchen, a neatly wrapped sandwich was waiting for me. It was a BLT with egg and cheese added. Thank you, thank you, I thought as I put my hands together and started eating.

While eating the sandwich, I searched on my phone for clothes that would suit Sis.

Plump… no, what was it again? Oh right, glamorous figure.

「Glamorous body type + summer coord」

When I searched for images, everything that came up was the same as what she usually wears — outfits designed only to hide her body.

I added “sexy” to the search. Hmm, mostly swimsuits… Oh!? These denim hot pants are erotic! These would definitely look good on her. …Wait!? This one has a see-through part on the chest! This would definitely look good too. Belly button exposure is nice~. What the hell is this!? A bodysuit? This is an insanely high-leg cut! And there’s a snap at the crotch!? What do you even open this for!? It’s way too erotic! It would definitely look good on her!

Crap. At some point the original purpose had completely changed.

Still, it was a meaningful use of time. I learned that something called a “bodysuit” — an erotic piece of clothing — exists in this world, and my knowledge grew.

“Erotic, huh…”

My own voice sounded strangely loud, but since the room was dead silent and I was the only one home, that was obvious.

…Maybe I’ll ask Shiori to wear one next time. For now, clothes can wait until later. Even after that, until it was time for my part-time job, I kept lazily searching for makeup styles and hairstyles that would suit Sis.

I got tired of the internet and started catching up on some novels I had saved. Time flew by, and it was almost time for work. Today’s shift was 5 PM to 10 PM. I had to leave soon.

It’s about a 20-minute bus ride from home. I arrived at the high-class yakiniku restaurant with plenty of time to spare, 15 minutes early.

When I entered the break room, I greeted everyone: “Ossu~”, “Osamasu!”, “Ah, good morning. Please take care of me today.” After passing through the break room, I changed into my uniform in the locker room.

…Jackpot!! Reina-san is here today! I wanted to ask her about Sis’s image change.

Reina-san is a second-year university student and should go to the same university as Sis. There’s definitely no connection between them — their personalities are completely different. No matter who looks at her, she’s a stunning woman. Every time I see her, I wonder why someone this beautiful is working at a yakiniku restaurant.

She has a slender body with feminine curves, a modern face like it came straight out of a fashion magazine’s makeup feature, and light brown, loosely curled long hair (currently tied up for work) that’s not too flashy. Unlike Sis, her hair is perfectly cared for and glossy. Her nail color is always different too. While thinking that this must be what “Minato Ward girls” look like, I returned to the break room. By the way, I call her by her first name because there’s another staff member with the surname Takahashi.

When someone this sparkling is around, the whole space gets judged based on them. In this small part-time job world, Reina-san feels like the protagonist.

Some people shrink back and keep their distance from the protagonist, while others talk to her with eyes that are way too ambitious for their status.

I’m neither type. I get along well with every staff member equally. Since I’m the youngest, everyone dotes on me. I think they see me like a little brother.

“Yo, Terumi. Today’s gonna be crazy busy. It’s a three-day weekend. Do your best!”

Murakami-san (the typical university guy who was talking with Reina-san) called out to me.

“Ossu. Yeah, I kinda had a feeling. Is it fully booked?”

“Of course. Looking at the reservation sheet, we’re packed for like three full turns. Ugh, this sucks. This is my fourth day in a row.”

“Good morning, Shimizu-kun. It’s okay! We have a lot of staff today. Let’s do our best!”

I was thinking Ugh, so annoying, but just hearing Reina-san say that immediately switched me to a positive mindset. As expected of the protagonist. Is this what they call an “ageman” (lucky girl)? Or maybe I’m just easy.

“Let’s do our best! By the way, Reina-san, you curl your hair yourself, right?”

“Eh? Yeah, why?”

“There’s someone with really bad natural curls who’s struggling, so I was looking for good hairstyles. Your hair always looks so glossy and beautiful, so I thought I’d ask for reference…”

“Eh, really? I’m glad. Ah, but for natural curls, there’s thermal straightening and stuff, but I hear maintenance after it grows out is pretty annoying.”

“Hey hey hey, what are you trying to pick her up for? You Z-generation kids are so bold these days.”

The typical university guy interrupted with a tease. You’re basically Z-generation too, I thought, but I decided to support him since he’s always desperately trying to get closer to her and passed him the ball.

“N-no, it’s not like that. She’s genuinely worried. But you think so too, right Murakami-san?”

“Eh? W-well, I’ve never really paid attention, but… yeah, I guess?”

What the hell, man? He completely whiffed my perfect through-ball. And we’re talking about hair — look at her hair, why are you staring at her chest?

I’ll have to bench Murakami for missing that pass.

“Eh~, I’ve thought this since I first met you, but your hair is always so silky.”

“I don’t do anything special. Maybe it’s because I’m careful with hair oil and styling.”

“Hair oil. I see, that’s what I wanted to know. Also, your nails were beige-ish before, but today they’re a light pink, right?”

“…Eh? You notice that? You’re amazing, Shimizu-kun. You have talent for beauty stuff.”

“Fufu, beauty talent, huh. It’s because I don’t have any that I’m struggling. Also — isn’t it a bit much for a restaurant job? Some people have really flashy nails, but yours are always natural-looking, short, and neatly shaped. I’ve always been impressed whenever I see them.”

“……Thank you.”

Reina-san made a fist and hid her hands. …Crap, that might have been too creepy. Just because she’s older doesn’t mean everything is allowed.

“Ah… sorry! I wasn’t staring creepily or anything! I was just impressed!”

“Hey! You horny brat! Time to start prep!”

“No, I’m not horny! Alright, let’s do our best!”

The atmosphere got a bit weird for a second, but Murakami-san saved me in the end. I’ll let him stay on the bench for now.

I thought Reina-san would respond with her usual mature smile and tease me like an older sister, but…

Reina-san. She doesn’t have a mysterious aura, but she’s full of mysteries. Why is she working at a yakiniku restaurant? Please tell me.

The bags and accessories she carries are all brand-name, and her style has no gaps. There’s a chance she’s doing sugar dating, or maybe she works at some insanely high-class escort place… Or with that beauty, it wouldn’t be strange if she already has an IT company president as a sponsor…

I’m curious, but I shouldn’t pry too much. I like this place and don’t want to make it awkward. Besides, everyone has some secrets.

Alright! Even if it’s busy, it’s only 5 hours! Let’s do this!

Chapter 013: Nostalgic Virgin

The restaurant was hectic. Orders kept pouring in one after another. Customers cheered things like “You’re working so hard even though you’re young,” and somehow I managed to get through it.

Since I’m still in high school, unlike the other staff, on late shifts I get a meal allowance and finish 10 minutes early.

I quickly changed and left the locker room. I sat down at the folding table in the break room and opened the wrapped staff meal I had just received. It was horumon gukbap (spicy tripe stew). The taste of a high-class yakiniku restaurant — undeniably delicious. But when compared to my sister’s cooking…

Click. The sound of the door opening.

It was still 5 minutes before closing time at 10 PM. I looked toward the door to see who it was. It was Reina-san.

“Good work today.”

“Ah, you too. You must be the most tired though, Reina-san.”

We both worked the floor, so I knew exactly how busy she was. Customers always tried to hit on her whenever she approached their tables.

“That’s not true. Shimizu-kun, you were moving twice as much as me. Sorry, and thanks for the help.”

“No no, dealing with customers is way harder. By the way, what’s up? You’re leaving early today?”

“No, not really… You were asking about hair earlier, right? So I thought I’d teach you.”

“Eh? Right now?”

“Ah, not right now… I’ll send you what I use later, so give me your ID.”

ID… wait, she means messaging ID!? No way…

I froze for a second at how unreal Reina-san’s words sounded, but I’m not dumb enough to miss a chance like this. I immediately took out my phone.

“Eh!? Is that okay? Thank you so much!”

I showed her my QR code. She scanned it and sent a stamp of a rabbit bowing its head saying “Nice to meet you.” The gap was too cute.

“Thank you! It’s not just hair — I also wanted advice on makeup and clothes.”

“I’m not sure how much help I can be… Wait, this is for your girlfriend, right?”

It’s not a girlfriend. It’s for my sister, but saying that out loud sounds like total siscon and is embarrassing. I gave a safe answer to her teasing smile.

“Nah, it’s not a girlfriend.”

“Not? Suspicious~ Well, whatever. I’ll send you stuff later!”

“Thank you, that really helps. Good work today!!”

“Yeah! You too!”

She gave me a smile so bright it almost blinded me, then swung her ponytail and went back to work.

I never imagined I’d actually exchange contacts with Reina-san. But I’m not that pure. If we were closer in age, she probably wouldn’t have given it to me. She sees me as a “kid” rather than a “man,” and knows 100% that nothing romantic would happen, so she felt safe. Still… I’m so glad I got this part-time job!!

In high spirits, I finished my horumon gukbap and headed home with steps so light I felt like I had wings.

“I’m home,” I said as I opened the living room door. The two women were watching a movie together.

“Welcome back~ Good work. Go take a bath.”

“…Welcome back.”

On the sofa, Sis was sitting in her triangle position wearing the T-shirt I gave her. Mom was sprawled out lazily like a sleeping Buddha.

After taking a bath and returning to the living room, the movie had just ended and they were both heading to their bedrooms.

“How was it? Did you buy clothes too?”

When I asked, Mom answered sleepily while stretching.

“We bought a lot. But it took so long to find clothes for this girl that I barely got anything for myself. There aren’t many sizes that fit her.”

At Mom’s words, Sis curled up like a pill bug. This woman really has zero delicacy.

“What kind of stuff did you buy?”

“They’re over there. Yeah, those bags and everything. Yawn… I’m going to sleep now. Good night.”

Mom let out a big yawn and went into her bedroom.

Sis still wouldn’t make eye contact with me. The hug from this morning must still be affecting her.

I picked up the shopping bags from various brands (some I recognized, some I’d never seen) and asked her.

“Can I look?”

“…Yeah.”

Inside were tons of blouses, skirts, and other going-out clothes. She seemed to have bought a lot of proper outerwear. I still needed to see her actually wearing them to judge.

“Which one is your favorite?”

When I asked, Sis eagerly started digging through the bags. She pulled out a folded item, unfolded it, and held it up to her body.

Big, round black eyes met mine. A large inverted-triangle nose. Fluffy gray fur. It was a wombat.

She proudly showed me an apron with a huge wombat printed in the center, letting out a satisfied “Mufu~.”

I see. So she only endured the shopping trip to get this.

“That’s an apron. I meant regular clothes!”

“Mom picked all the clothes for me…”

“You only chose the apron yourself?”

“Yeah…”

“What about makeup?”

“She bought me some… Ah, she said she’d teach me tomorrow…”

“That’s good. I can’t wait to see you become more stylish, Sis.”

“It won’t… change that much… definitely.”

“It will! By the way, didn’t you buy any loungewear?”

She was still wearing my T-shirt with her baggy sweatpants. She was starting to look like a rapper.

“I didn’t…”

“You should’ve. You look like a hip-hop artist. You into hip-hop?”

“…Not really.”

Sis said it with a slightly pouty tone.

I had spent half the day researching clothes and hairstyles for her. I wanted to have a strategy meeting.

“Are you going to bed now, Sis?”

“………What about you, Teru-kun?”

She asked while staring intently at my face.

“I was thinking we could decide on your hairstyle and stuff, but if you’re sleepy it’s fine.”

“Then… I’ll stay up…”

She answered a bit eagerly.

“Great. Come look at this. I think this would suit you.”

I sat next to her and showed her short videos on my phone.

It was an account of a cute half-Japanese girl with a modern face. Her hair texture was similar to Sis’s, but her hairstyles were completely different. She didn’t straighten her hair and enjoyed trying various styles every day — a fashionable girl.

Sis squinted at my phone from a distance.

“No, come closer.”

“………”

She approached cautiously, as if wary I might do something to her again. Once I took off her glasses, she peered at the screen.

“How about this hairstyle? Center-parted bangs are nice too. Or look at this one — just curling the front pieces with an iron.”

“…Do you like this one, Teru-kun?”

“Yeah, I think it would look good. It’s stylish. Also, I asked my senior at work today, and she said thermal straightening exists, but maintaining it later is a hassle.”

“…Then I’ll do this.”

I had spent a long time searching through options, yet Sis answered instantly.

“Eh? Is that okay? What do you think?”

“I… don’t know… so whatever Teru-kun thinks is good… is fine.”

“I-I see. I’m not sure we can recreate this exactly, so let’s bring other candidates and consult with the stylist.”

I sent her the link to my carefully selected hairstyle collection. Oh right, she probably doesn’t have an Instagram account.

Her phone made a ping sound.

“Sis, you don’t have an Instagram account, right?”

“…I do.”

“Eh!? You do!? Show me!”

I was so surprised I accidentally raised my voice.

“I only look… I don’t post anything…”

The screen she showed me was full of wombat photos and various cooking images. After getting a bit closer to her these past few days, I realized her only hobbies were cooking and wombats.

“I see. For now, follow the account I just sent. Also, do you think you can explain it to the stylist?”

“…M-might be hard…”

Yeah, I figured. With her personality, explaining something she doesn’t fully understand herself is impossible. Can’t be helped.

“Want me to come with you? Only if you want.”

“……I want you to come.”

Sis sat in her triangle position, fidgeting and overlapping her long toes. Even though she’s three years older than me, her feet were smooth like a baby’s.

“Also, want to go buy new glasses? I’m starting to want some stylish ones too.”

“…Okay.”

“Let’s both do it. I’ll debut with glasses, and you’ll debut with contacts. Sounds good?”

“Y-yeah… really good…”

She must have wanted glasses too. Her cheeks were faintly pink and she looked incredibly happy.

“Then let’s go shopping together once summer break starts.”

“Yeah!”

Thump. My heart jumped. That smile is unfair.

“Alright, let’s go to bed. You’ll be busy studying makeup tomorrow.”

“…Yeah.”

“You heading up too?”

“Yeah… I will.”

“Okay, I’ll turn off the lights.”

I turned off the living room lights, and we both headed upstairs to our rooms. For some reason, I felt incredibly nostalgic. Just the simple act of climbing the stairs together.

This feeling is really nostalgic. What do you call this… homesickness… nostalgia… No, that’s not quite right. There’s no sadness or melancholy — just pure joy from the nostalgia.

Lost in thought, we arrived in front of Sis’s room.

“Good night.”

“…Good night.”

I watched her back as she went into her room. Being left behind alone.

That’s right… We used to sleep together a lot… probably… I think so… No, I’m sure we did.

When did I start sleeping alone in my own room? I have no idea——

But one thing I understood. This feeling is nostalgia.

Looking at Sis’s back, I felt a sentimental longing and a bittersweet attachment to the past.