"Mhm.. Mhm!..." The lewd sucking sounds from my sister's mouth reached my ears, making me feel lightheaded as I thrusted my shaft inside it.

I gripped on the back of her head and slowly plunged myself deeper inside of her mouth. I made a small grunt as I reached her throat and stayed still for a moment, granting myself some time to enjoy the pleasure of my member inside her slimy throat.

"Mmph!!!" My sister's eyes widened in surprise.

"What's the matter, Kotomi?" I smirked as I started to move again, reaching deeper and deeper down her throat with each thrust.

She looked up towards me with dazed eyes and half closed eyelids. Maybe she was starting to suffer from the lack of oxygen.

She made a small squeeze on my thighs as she was holding on to them.

I sighed and slowly took my member out of her wet and slimy entrance, feeling the bumps on her tongue rub against the underside of my manhood before I fully pulled away, leaving strings of saliva hanging from the tip of my shaft.

Her eyes brightened up a little and she coughed. "...Onii-san." She squeezed my thighs again. "Why are you doing this to Kotomi..."

I looked down on my member, admiring the viscous flow of my sister's saliva on my shaft. I made a small smile and kneeled down, in front of her.

"That's because I love you, Kotomi." I grinned and patted her head gently.

"...liar." She broke down into sobs and made a few small coughs. My little sister held her throat and gently massaged it. 

"If you really love me, then why are you hurting me, Onii-san?..." She looked away.

Seeing and hearing what my Kotomi did and said, I felt something twist within me.

Before I knew it, I held her shoulders firmly and leaned forward in order to whisper to her lips, "I'd rather be the one who will hurt you than some other boy who likes you."

Her sobbing stopped and I felt her body shiver.

I planted a kiss on her lips before pulling away and taking my hands off her.

She looked at me, her lips still quivering.

"Don't you see, Kotomi? This brother of yours loves you very much." I grinned. "It's all your fault for being so flirty with those boys." I continued, "It's your fault that this is happening, Kotomi... It's because you're just so cute, kind, and gentle..."

"I don't want you to go to anyone else." My grin faded as I caressed her cheek. 

"You're Onii-san's girlfriend and if you ever feel like leaving, I'll break you until you can't live without me anymore, I promise."

A week earlier...

I just got home from school. I went to the kitchen in search of food since I was hungry from club activities. 

I opened the fridge and took out a can of softdrink and gulped its contents down. The sound of footsteps reached my ears as a petite figure quickly went down the stairs.

My little sister is a really cute girl, younger than me by four years. She's kind, gentle, understanding, and helpful towards me. 

Since it came to this, with my adolescent urges and the fact that we live together in the same house, only the two of us... I started feeling love and affection that exceeded the limits of what should be felt towards siblings.

However, I controlled and held myself back every time that me and Kotomi get to be alone in a room or during dinner. I care for her and I won't let my feelings get in the way of our relationship. 

I still love her as my little sister after all.

"Onii-chan! You're home already, welcome home!" Kotomi ran to me and gave me a back hug.

The surprise sent a pleasant tingle through my spine and I smiled. "Yeah, I'm home now." 

I slowly turned towards her and ruffled her hair. 

"E-Ehh..." My little sister looked up at my hand and blushed. "Geez, I just fixed my hair awhile ago."

Seeing her cheeks redden made mine do the same. So, I laughed a little, trying to shake away the fuzzy atmosphere I was in, in my head. 

"Whatever, you still look cute, Kotomi." I grinned.

"I believe you, Keito-oniisan." She smiled.

An hour quickly passed by and we were talking over dinner when I noticed that Kotomi's cellphone was on top of the table.

"Oh, hey, Kotomi... It's rare for you to bring your cellphone to the table." I said while I chewed the curry we're having for the meal this night.

"Y-Yeah... Ehehe... It's just maybe someone will text me." Kotomi looked to the side with an embarrassed expression.

"Oh, you made friends?" I asked her.

"M-Mhm!" She nodded her head towards me earnestly.

I smiled. I stood up and gently patted her head. "That's good, Kotomi."

"Mhm..." She looked down, her fingers fidgety.

I was having doubts about her reply and my heart clenched, knowing that she was lying to me.

A few minutes went by in silence.

"I'm finished now, Onii-chan." Kotomi said. She stood up and put her plate in the sink, then she proceeded to go to her room.

Then, I heard a small beep come from her phone. 

"Wait, she left it behind? I have to bring this to her." I hurriedly ate the last few spoonfuls on my plate and went to get the phone.

I was tempted to turn it on and look at it. But, I should respect her privacy, I love her that much, after all.

I went upstairs and before I knocked into the room, curiosity took over me and I opened her phone.

There was a notification in the lock screen that read: 

Unknown:

Kotomi-san, I really like you. Please go out with me! I promise to do my best if I get to be your boyfriend!

"Huh..." I felt my hands go cold.

I heard a sudden click from the door and the knob turned. 

"My phone!" Kotomi came rushing out and bumped straight into me.

I looked down towards her with blank eyes.

I know she has a great personality and that lots of boys like her, but why did she give him her number?... No, it's too early to consider that. Maybe one of Kotomi's friends gave away her number.

What I'm sure of is that, my little sister is going to be taken away from me by this bastard who thinks he can make Kotomi happy.

"Tch." I felt something twist within me.

"What's the matter, Keito-oniisan?"

Kotomi asked me with a surprised look on her face, clearly she doesn't know about the text message.

I sighed. "You forgot your phone." I handed the cellphone to her.

She gently held it. But, as she tried to pull away, I tightened my grip, not letting go.

"E-Ehh?" She looked at me with that surprised look again.

"Somebody texted you." I looked to the side. "Somebody who wants to be your boyfriend."

"O-Oh..." Kotomi suddenly seemed uncomfortable. "I'm really sorry that I haven't told you about this yet, Keito-oniisan." 

I felt rage swelling up inside me.

Before I knew it, I held Kotomi up and threw her to her bed.

"E-Eh? Keito-oniisan?" She scrambled backwards, panic evident in her face.

I settled her phone on her desk, a little harder than I supposed, making the table shake a bit.

"O-Onii-chan..." Kotomi's legs trembled.

I said nothing. My mind was blank except the thought of having my little sister taken away from me. The little sister I love so much. I was scared that I would lose Kotomi... The fear I felt fueled my anger and made me lose control.

My incestuous feelings took over me and led me to a blind rage. I knew the consequences if I continued, but, right now, I didn't care. Nothing else mattered, except keeping Kotomi to myself.

"I'm sorry." I climbed onto the bed and crawled over to my frantic little sister.

Leaning forward, I then whispered, "I'm really sorry, Kotomi." I gently kissed her ear.

I heard my sister gasp, "T-Then stop this, Keito-oniisan..." 

She tried to push me away with her slender arms, but the frailty of her rejection felt more like a caress and it led to my arousal.

"I can't do that... I don't want to lose you, Kotomi." I let out heavy breaths against her neck, making her feel sensitive

"Y-You won't!" She struggled under me.

"I don't know about that yet." I said as I leaned down and started kissing her neck.

"K-Keito-oniisan..." Kotomi struggled more, but this time, there was trembling in her hands.

My hands ran up her blouse, feeling the front side of her body through the light fabric. Kotomi only shivered in response, her lips and eyelids shut tight.

"I'm really sorry." I whispered again. I really am regretful, but I don't want to stop... I need to mark Kotomi... I need to put a sign on her body that will make her mine... I need to make sure that my beloved little sister won't leave me for some other guy.

"I've made up my mind, Kotomi." I kissed her cheek and pulled away. 

"E-Ehh...? Please tell me you made up your mind on stopping this..." She looked at me.

I shook my head. "Sadly, no." I looked down. "I made up my mind, I want to have sex with you." All these pent-up feelings of holding back from touching my little sister urged me to make love to her, right in this moment.

Kotomi's eyes widened. "N-No, that's wrong, Keito-oniisan!..." She tried to straighten up so she can run away but I held her down and pinned her to the bed.

"N-No!!..." She squirmed, trying to break free.

"I love you, Kotomi." I said as I closed the gap between our faces, leaning down so as to kiss her.

"I-I." She looked away. "I love you too, K-Keito..." Kotomi pursed her lips before saying her next words. "But, this is wrong... I know this is wrong, so please, stop this before things get worse." Then, she turned her face towards me.

I was speechless, being unable to comprehend the fact that my little sister, who was still a middle school student, thought this much.

But, what affected me more were her first words... 

Kotomi said that she loves me.

But, was it the same as mine? Does she love me as much as I love her? Does she feel the same as me?

"...Y-You just said you love," My breathing quickened,  "me..."

"I do, Keito-oniisan..." She smiled a bit. "And I know it's wrong." 

Those last words struck me like lightning. But it didn't make me feel the slightest bit of hesitation.

I leaned down and kissed her.

"Mhm-" Kotomi's eyes widened in surpise.

I slid up her blouse and started groping her petite breasts. I didn't feel any remorse or guilt... this is the right thing to do, so that Kotomi won't leave me.

She told me herself that she loves me. If she really does, then what's wrong with doing this? Because we're siblings? I don't care. 

I have more right than any person in this world to love Kotomi. 

I pinched her nipples with enough pressure for her to gasp, "A-Ah!-" 

I took the opportunity to slide my tongue between her lips and into her mouth.

"Mhm- Mmph-" Kotomi tried to resist by closing her lips, but I forced my way in. I reached her tongue and played with it, coiling my own around it and licking it from time to time while I continued to feel her body.

As I pleasured my little sister, I felt arousal spreading through my body, making me feel warm especially in my place down there.

My cock soon went hard, making a large bulge in my shorts which felt almost painful.

Muffled moans came out of my sister's lips as I continuously teased her erogenous zones while I kiss her. 

I saw it as something particularly lewd and I can't hold in the excitement anymore. I need to relieve myself of this pent-up arousal and I also need to make sure that my little sister knows just how much I love her.

I pulled away slowly. "Kotomi, tease yourself for Onii-san... okay?" I asked her.

She was still catching her breath. She had a dazed expression on her face and her lips were opened to make small sighs. The reddening of her cheeks made her extremely cute, to the point that it was erotic.

"I-I feel hot... K-Keito-oniisan." Kotomi looked down at her body before she slowly slid her hands to her sensitive places, one on her breasts and one on her womanhood. I guess Kotomi heard what I said since she started doing herself, making small whimpers and moans while she was at it.

"Keito-oniisan!... Keito!... Keito!..." Kotomi's cute tiny voice was moaning my name and I can't help but get more aroused by her.

I slowly took off my shorts and my underwear, revealing my long, hard, and hot shaft. I started stroking myself while I looked at my little sister pleasuring her body by herself.

"Kotomi... Kotomi..." I said under heavy breaths while I stroked myself to my sister's erotic actions.

"K-Keito!" My sister's voice trembled as she rubbed her slit harder, presumably, she was close to her climax.

Being unable to keep my head clear, I held Kotomi's right thigh with my left hand and gently lifted it to the side, opening up her legs so I can put myself between them. I decided that Kotomi was already wet enough, so I stopped stroking myself and whispered to her ear that she should pause from doing her own body.

She reluctantly nodded, she was, after all, close to her climax, and for it to be ruined just seems to leave a bad taste.

"Don't worry, Kotomi..." I said under my breath as I looked my little sister's body, taking into account every little detail I can see, taking into account all the details I'm about to feel.

"I'm going to make you feel good in a bit, just wait..." I said as I slid her panty down. 

"Keito-oniisan..." Kotomi was still in a daze, presumably because she was feeling immense pleasure a moment ago. Her eyes were only half open and she made small sighs. 

"Kotomi, Onii-san's going to make love to you now..." I lifted up her legs as I positioned myself between them and I made her wrap them around my waist.

It all seemed like a dream, but, I was finally going to be one with my beloved little sister. I can't ask for anything else. She's all I need.

I gently rubbed the head of my manhood against her glistening entrance, checking out the wetness of her slit.

Deeming that it was already enough, I started to penetrate my little sister, slowly sliding in my shaft into her, making sure that she didn't feel much pain. However, being slow won't help with taking away the pain of tearing her hymen. 

"A-Ah!" Kotomi exclaimed in pain, her eyes turned alert as soon as I tore through the only thing that symbolizes her virginity. 

Small drops of blood dotted the blanket beneath Kotomi, and the whole scene was surreal for me.

"O-Onii-san!" The wrap of her legs around my waist tightened made it all reality however, and, forced me to go deeper. "I-It hurts-" Tears formed in the corner of her eyes.

"I know." I said, wiping the tears away. "It'll feel good, real soon. I promise." My little sister nodded slowly.

I was trying my best to stay focused on taking it slow for Kotomi, but her insides just felt really good. It was really tight and it squeezed all around my shaft, sucking me in every time I pull away after a thrust.

A few minutes later, the pained whimpers that Kotomi made were replaced with erotic sighs and moans as I continued to thrust into her.

That was when I came to my senses.

I stopped moving and Kotomi sensed it just right after. "Onii-san?..." She looked at me. Her face and body was riddled with sweat.

"I'm sorry." I looked down.

"Idiot." I heard a small mutter.

"W-What?" I stole a glance at her.

"Finish what you started, you dumbass." Kotomi threw her arms around and pulled me down. 

Then, I felt myself get surprised as a sudden warmth covered my lips. 

Kotomi kissed me on her own... There was nothing else to do or think of, so I kissed back.

"Mnm.. Nhaa.. Fuwa... Nhaa.. Keito-oniisan..." 

"Mhm.. Kotomi... I love you, Kotomi..."

"Me too, Onii-san... I love you too, Kotomi really loves you."

-present time-

"Geez, Onii-san, why do you like this kind of play?" Kotomi pouted and looked to the side.

"E-Ehh... You see, it's probably because I want to keep on reminding you that you're mine... and that, I don't want you to leave me, Kotomi." I patted her head and smiled.

"But still... you're scary sometimes, you know?" My little sister's cheeks visibly reddened.

"Do you hate it?..." I leaned towards Kotomi.

"N-Not really..." She blushed more.

"Then, it's alright, ain't it?" I kissed her cheek gently.

"M-Mhm..." She turned towards me.

"I love you, Kotomi... and I'm sorry for every bad thing I did." I smiled a bit.

"You should be. Hmph." She crossed her arms.

"Haha, yeah yeah..." I pinched her cheek. "No I love you too?"

"Geez... I love you too, Keito-oniisan..." She looked at me with a small smile on her face.

"What am I to you, Kotomi?" I always asked her this question ever since last week.

"You're my perverted lolicon older brother." She stood up and walked over to me. "And, you're my boyfriend, Keito-oniisan." She gave me a cute grin.