I'm the Only One Who Doesn't Know My Sister is My "Stepsister" ~The Beautiful Twin Sisters Want to Seduce Their Oblivious Brother~ - 2

Chapter 2: My Little Sisters Are Being Strange

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The long summer break finally came to an end and the sign of autumn were gradually approaching now that we had reached the end of September. I, Yuuto Otaru, headed straight home as soon as the last period at school ended. I was feeling incredibly sleepy since I had stayed up late watching a certain VTuber stream last night. The dark circles under my eyes were prominent, but since the dark circles were a regular occurrence in my life, I didn’t pay much attention to it. I was thinking of relaxing and watching some VTuber highlight clips once I got home. 

“Thinking about it… It seemed there was a lot of noise coming from the room next to mine. It was pretty late though… Maybe it was just my imagination? Hoaaam~”

While yawning lazily, I passed by the park on my way home. There, I noticed a group of elementary school kids playing excitedly. Some were playing tag, some were building sandcastles. They were all playing different things. I remembered that I used to play with my friends at the park like them too while taking care of my younger sisters back when I was in grade school.

“When I was little, huh…”

Looking back, my golden age only lasted during my childhood. Back then, I was always at the top of my class, both academically and in sports. The girls were attracted to me without any effort from my side. I had lots of friends and every day felt so bright and full of joy. I wished those golden days could last forever, but now… Things were different now. These days, I was just slightly above average in both studies and sports. I was far from being at the top. My relationships with friends gradually became colder and I spend most of my time by myself, watching VTuber streams. 

“And back then… My relationship with my little sisters was good too.”

My feet somehow stopped at the entrance to the park. I had twin little sisters. They were still in their third year of junior high school. They used to be so adorable, but when they entered junior high school, they suddenly hit their growth spurt. Their transformation was so shocking that everyone was surprised by it. They grew taller, their faces became even more refined and their body figures became absolutely stunning. They became the talk of the town now, known as the ‘beautiful twin sisters’. As their older brother, it was only natural for people to compare me with them. I felt the pressure every single day and so, I worked hard to get accepted into the most prestigious private high school in the area. It was my pathetic last ditch effort in trying to maintain my pride as the big brother… Or so I thought. It turned out, my classmates were way smarter than I imagined. It was not a surprise though, since that school had the highest average deviation score after all. I could barely keep up with my classmates and my test scores were… To put it simply, horrendous. 

“And now… I’m addicted to watching VTuber. It’s a way for me to escape from the reality of my life… I’m just a gloomy, introverted guy now. I’m really a failure, a useless member of society.”

Feeling ashamed of myself, I slowly made my way back to our apartment building. I took the elevator up to the 6th floor and unlocked the door to unit 604.

“I-I’m home… Hm?”

Judging from the two pairs of shoes at the entrance, it seemed my little sisters had gotten home before me. My little sisters might be twins, but their personalities and appearances were the complete opposite. The older twin, Yuuri Otaru, was an honor student at the top of her year. While the younger twin, Kairi Otaru, was a blonde gyaru. Yuuri with her black hair and Kairi with her blonde hair. The two of them might be the polar opposites, but they were both equally beautiful. In the past, they were my adorable little sisters with identical appearances and they adored me as their older brother. They always begged me to play with them and whenever we went out, they always insisted on holding my hand. However, it seemed they had entered their rebellious phase when they got into junior high school. They were cold and curt not just to our parents, but even to me, their older brother.

One clear example… Mom was doing the laundry the other day and Kairi immediately yelled in a voice loud enough for me to hear.

“Stop washing my clothes together with Onii’s!!”

She obviously yelled that loud so I could hear her. Sure, maybe she acted like that because she was a gyaru at her rebellious phase, but it wasn’t only Kairi who hated me though. Even Yuuri, who was always kind and polite to everyone, went out of her way to come to my room and exclaimed. 

“Onii-chan, make sure you wait at least 30 minutes after I use the bathroom before you go in. You HAVE to wait at least 30 minutes after me, okay?!”

I understood. Both Kairi and Yuuri were at the age where they started feeling conscious of the opposite sex, so maybe they felt uncomfortable around me. But still, remembering how clingy and affectionate they were with me back in grade school made their current cold attitude toward me so excruciatingly painful. Back in the day, us siblings were so close that we would never worry about things like that. However, everything changed the moment they hit puberty. 

“Haah…”

Sighing, I looked down at my feet and something caught my eye. It was a pair of loose socks. Kairi must have tossed her socks aside haphazardly into the corner of the entryway. She probably expected someone would’ve picked it up anyway. If our relationship remained the same as in the past, I would’ve scolded her as her older brother,“Kairi! You need to bring your clothes to the laundry!” However, things were different now. 

“…There’s no helping it.”

I muttered to myself as I picked up the loose socks with my thumb and index finger, since these used socks must be dirty. I was thinking of tossing them into the washing machine in the laundry room. I couldn’t scold my little sister anymore, not with how they had been treating me the last few years. They were so cold toward me that our relationship had deteriorated. If I tried to scold them, our relationship would only become worse. Besides, unlike them, I didn’t have any special merit. I was just an average guy. Average score, average face, average in everything. I could feel there was some sort of unspoken hierarchy within our household and I knew as a mediocre guy, nothing I said could stir them. There was no way they would be willing to listen to a lecture from a pathetic older brother like me.

“Haah… I better wash my hands and gargle.”

Letting out yet another sigh, I washed my hands and gargled in the bathroom before heading to the living room. The lights were on, so someone must be there. Maybe either Yuuri or Mom. 

“I’m home… Huh?”

There, at the large table in the middle of the living room, I saw Kairi, the gyaru with bright blonde hair. She was busy writing something with her mechanical pencil and she was dressed casually in a loose t-shirt that exposed glimpses of her cleavage and tight denim hot pants that showed off her thick thighs perfectly. Kairi often wore revealing clothes around the house even though I was here. It seemed she didn’t even see me as a guy. 

“…”

She was writing something down in silence, so focused on whatever she was doing that she didn’t realize I had come home. To be honest, I never thought I’d see the day when Kairi, the delinquent gyaru of the house, would actually hold a mechanical pencil at home. I thought she didn’t have any interest in school and that she would spend all her free time playing with her smartphone…. 

While my brain was still processing this unexpected sight, I quietly approached her. Then, I noticed she was reading a book titled “Middle School Math for Dummies.” The title almost made me laugh if I weren’t shocked to my whole core. My eyes widened in shock. I almost couldn’t believe it if I had read the title right. 

“…Ka-Kairi…?”

“-?!”

When I called out to her, Kairi flinched in an exaggerated way that reminded me of a character from Studio Ghibli movie. Shiver ran down from her back to her shoulders before she slowly turned to look at me. Her expression was the epitome of fury. She was glaring straight at me.

“O-Onii?! Don’t just call my name all of a sudden like that!! You scared me!!”

Flustered, Kairi quickly tried to hide the textbook on the table with her voluptuous chest. Her large chest was pressed down hard against the table, crumpling the open pages of the textbook beneath her.

“Ah…! Geeeeeezzzz!!! Because of Onii, my textbook got all messed up!!”

“So-Sorry…”

Kairi yelled at me with such intensity that her blonde hair seemed to bristle up. 

“I must be getting in your way, huh? I will just grab some barley tea and head to my room. Just keep studying, don’t pay me any mind. I’m sorry. I really am.”

“Huh…? N-No! I… Umm… I….”

Kairi’s angry expression turned into one of distress as she fidgeted awkwardly. Strange. Normally, Kairi would’ve said something curt like,”If you’re sorry then give me some money and get on your knees to beg forgiveness from me!!” But… Kairi looked like she wanted to say something. She seemed to be at her wits’ end and even though she was the one that called out to me, she still hadn’t gotten any word out.

Somehow, I’m feeling awkward.. Ma-Maybe I should say something first. 

“Ah, right. I put your socks that you left at the entrance into the washing machine.”

“Huh? My knee-highs?”

“Yeah. Someone could step on them and slip if I just left them there.”

“…—anks.”

“Hm?”

“…Tha-Thanks.”

Tha-Thanks…? She said thanks?! Impossible! Kairi, who was in the middle of her rebellious phase, actually thanked me?! Something was weird here. Something was definitely off!! And the mystery was only getting weirder from this point onward.

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