This is a print version of story Side Effcets by samurai1999 from

Side Effcets

I gt this story from a friend of me (not on xhamster). I loved it, so I asked her and got her permission to repost here

After I graduated from high school, I decided not to go to college or university. I wanted to earn money and see the world, because I thought I am good at English. But before looking for a job, I wanted to spend some time in Tokyo. I grew up in Osaka and the Kansai area is pretty familiar to me. But Tokyo was something different, more modern, and more international.
My 18 months older b*****r went to university in Tokyo and he allowed me to stay in his small flat. It had two small tatami rooms, each with 6 tatami mats, one kitchen/dining room and a bath.
Even though our f****y cannot be considered ‘poor’, our dad did not give my b*****r, his name is Yuta, much allowance. “You need to work, to see how it feels to earn your own money!”
When I went to live with him, I had no idea what work he was doing, but I was soon to find out.
On my third day at his place I found this white plastic bottle beside his futon while cleaning his room. It was a bottle for medical pills and had the name of a well-known hospital on the label. But instead the name of the d**g and a description about the dose, it only had the following number hand-written on it:
I shook the bottle and heard the dry rattling sound of a few large pills bouncing off the walls. It contained ten elongated pink pills.
I didn’t think much about it and nearly forgot to ask him. But after our dinner (we had Oyako-don) I asked him
“You sick?”
“Hnnn nnn.” He made a negative sound while shoving the next portion of chicken into his mouth. He eats a lot.
I propped my elbows on the table and leaned forward.
“But what about those pills?”
“Work.” And he continued chewing without looking up.
He gulped the rice down with some Oolong tea.
“Clinical trial…stupid.”
“I am not stupid!...Just because I am 18 months younger than you!” I always have hated it when he called me that. Memories of our fights as k**s erupted in me. Memories, in which he always had won the fight.
“Calm down sweety…just k**ding….it is easy money, you see?”
“Those trials!” He raised his eyebrows. He cleared his throat and sounded like a doctor. “Phase III clinical trials. Volunteers take some pills, write a report how they feel, and get a check-up in regular intervals.” His voice became normal again. “…. and I earn tons of money.”
“But isn’t it dangerous?” I was astonished at my concern for him. A few years ago I couldn’t have cared less if he had wanted to kill himself, but now I felt worried.
“Look, those pills have been tested in a****ls….no side effects….then, they test them with healthy people.” He pounded his chest with his fist. “Guys like me!”
I could not help but acknowledge that he really looked healthy. He had been in a rugby team in high school and ran long distance. His eyes were sharp and his whole body radiated confidence and power. He was full of energy. Thinking about it, maybe that was why I didn’t like him that much.
He had finished dinner, got up to his room and came back with the bottle.
“Here, I show you.” He popped a pill and drank a glass of water afterwards. I couldn’t help staring at him. I knew that pills don’t work right away, but I somehow expected he would turn green, or stopped breathing, or started convulsing.
“When did you start this time?”
“Two days ago. They always give 12 days worth of pills and I have to count them every day to make sure they don’t get lost, or I take too many.” He changed to the lecturer voice again. “This one has to be taken once a day, after dinner, with 200 ml of water.”
After a pause he added “Did you see any difference in me?”
“No, you are as arrogant as ever!” and I went to my room, hearing him laugh a short, rough laugh.
I heard him preparing the bath and after he had his soak, which took 20 minutes or so, I relaxed in the hot water. When I got out and dressed in my pajama, the light in his room was off and I heard his snoring.
I browsed the internet, chatted a bit with friends and just as I was about to call it a day, I heard strange sounds from his room.
“What are you doing?” Was he talking on the phone? “Get off me!!” No, there could not be any other person in his room.
Suddenly he pushed the door open and stomped into the living room. I jerked up from my seat and I just wanted to scold him “Hey, don’t scare me!” when I saw this funny expression on his face. Half troubled, half excited.
“Don’t do it, mom!” He was walking around the table, waving his arm behind him, as if his mom was chasing him. I was stunned. I had never seen anyone sl**pwalking before. He was on his second round around the table when I got up and stood in his way, stretching my arms to the front to stop him. The impact was stronger than I expected and it pushed my arms apart and he bounced into me. Luckily, this stopped him.
“Hey cool down, it me, Aki, you s*s!” He still seemed to be asl**p.
“Don’t do it mom, please! What shall I do?” He trembled. For the first time, I felt sympathy welling up in me. I wrapped my arms around him and told him in a motherly voice
“I am not doing anything. Relax.” To my surprise, my voice had an immediate effect. His breath slowly returned normal. Slowly, he wrapped his arms around me and gently pressed my head against his chest – my b*o is a full head taller than me. It was a very embarrassing situation. Here I was with my b*****r, and I had never been embraced like this by him before. He usually, while awake, was an arrogant bully, but now he wanted me to comfort him. So I did what I had never done to him (but to a couple of my boyfriends): I stroked his back, while I listened to his frantic heartbeat and felt his muscular chest slowly heave.
As he pressed himself against me, I could feel something else. Something that I had always enjoyed feeling with my boyfriends, or with the occasional one-night stand: his growing erection. It pressed through his boxer shorts against my tummy. But feeling this from my b*****r was so disgusting. I tried to push him away. But his embrace was too strong.
I pounded his chest.
“Stop it!” Now he obeyed.
“Yes, mom!” he dropped his arms. I stepped back and could not help to see the huge bulge in his shorts. Just at the top of the buldge there was a tiny wet spot. I knew very well where that came from – precum. But he was definitely still asl**p.
“Go to bed”, I ordered him, but I could not take the eyes off his shorts while he turned around, went to his room and got down onto the futon. He turned on his back, and started snoring immediately. But his huge erection did not weaken a bit. In my confusion, I closed the door to his room and laid down in my own room, trying to find some sl**p.

“Hi, s*s! Get up!” It was his usual bully voice that woke me from a short sl**p.
“I will be home as usual.” He barked. “Can you do me a favor?” He stuck his head through my door. “Throw the switch on the washing machine, will ‘ya?”
b*o was doing his own laundry, but he seemed to have no time that morning.
“Bye, s*s!” and he threw the entrance door shut. I was baffled. He did not seem to remember the embarrassing moments last night. Had he been really that deeply asl**p?
Against my conscience, I opened the washing machine. There was just one boxer shorts in it. I picked it up with the fingertips (which girl wants to touch her b*****r’s underwear?) and I saw a big stain on it’s front. I did not need to check any further. I immediately knew what it was. And it was a huge load! I dropped it back into the machine and pushed the ‘start’ button.
I don’t remember clearly what I did that day, but the images of the previous night with my b*o were burned into my memory. His babbling about mom, his embrace, his immense erection and the huge load that he must have shot into his shorts during that night confused me.
When he came back that evening he saw the dried boxer shorts on his chair.
“Thanks, s*s.”
“Why do you make me switch on the machine just for one pair of pajama shorts?” I inquired.
He sounded a bit sheepish when he said “Well, they are my favorite ones!”

Our routine was the same that evening. Dinner, bath, he swallowed his pill, and went to bed.
I went to take a hot bath and then sat at the dinner table, not knowing what to do if he would come out of his room sl**pwalking again. I was still deep in my thoughts when I heard him moan.
“Mom!......Mo-om?” I heard the rustling sound of his bed sheets and moments later the door to his room opened. He just stood in the frame, eyes wide open. He stared at me, but I wasn’t sure if he saw me. His right hand was in his boxer shorts and he slowly stroked his hard cock.
“There you are, mom!” without stopping to work his cock, he slowly walked the ten steps or so from his door to the table. He was much calmer than the night before. His head slightly tilted to the side, he seemed to expect something from me – or his mother, in his imagination. I stood up.
“Mom?” I still don’t know what made me do it, but I decided to play the game.
“Yes, my dear?” It felt so strange. My face was different, my frame was much smaller than mom’s, my voice was different, but it seemed as if my own b*****r didn’t realize the differences.
He dropped his shorts and his full manhood was revealed. While he was stroking his cock, the foreskin periodically covered and uncovered the deep-red tip. I saw a drop of precum emerging.
It was so gross. b*****r and s****r, just feet away. He was sl**p-walking, and I had no idea what he was seeing in his dream or what he would do next. If he wanted, he could **** me on the spot and I would be defenseless.
“Mom, can you do to me …… what you have done the other day?” he sheepishly asked.
Was he remembering some actual thing that had happened in the past, or was this all in his dreams? I had no idea. But I was scared if I would not continue to play the game, he might wake up or do something unexpected.
“Tell me again, sweety, what did I do?”
His face lit up. “Your mouth….your lips….your tongue…..” his voice drifted away. For the first time he broke the eye contact with me and looked down at his cock.
I stepped towards him and reached out to grab his hot rod.
“You want me to kiss your cock?” I whispered. The thought made me hot, despite that I hated my b*****r for being such a jerk (when he was awake). I felt a surge of power in me - a power to control my b*****r. I felt that he would do anything while he was under the influence of that experimental d**g. I decided to try something and be more bold. I decided to pay him back. So many times in the past he had humiliated me. It was time to humiliate him.
“Only if you first lick me first!” I commanded. It only took me an instant to step out of my pajama. I put one leg on the chair and commanded him.
“On your knees and lick me. Put your tongue deep into my pussy!” He immediately obeyed and the moment he started, I knew that he had done this before. He was good at it, so good. Sucking my lips, flicking his tongue over my clit, pushing his tongue deep into my wet pussy, and then starting all over again. He sent waves of pleasure through my body. He did not mind my pubic hair when he opened his mouth wide to engulf my whole womanhood. He stopped stroking his cock and gabbed my ass with both of his strong hands and spread my cheeks wide.
Wave after wave flooded me. When he paused licking me to get a breath, he would push his fingers deep into my pussy, working her tirelessly.
“You taste different, mom!” without stopping his pleasure work, he made that shocking confession. So, he had licked mom in real life, it seemed. He had an i****tuous relation with his own mom. I panicked at first, but immediately realized that I was having the same i****tuous relation with my own b*****r. And it felt good.
While he was continuing his flicking and sucking, I pressed his head deeper onto my triangle. In order not to blow my cover, I had to think of something.
“Women taste different, depending on the time of the month.”
“You taste good, mom.”
While the waves of pleasure flooded me, I remembered that my goal was to humiliate him, not to have fun for myself. So, I reached behind me and grabbed my cell phone. I pointed the camera downwards and took a series of quick pictures, while he did not realize it. Even though his face was buried deep in my triangle, one could recognize him. I was sure that no one would recognize me as the women with the spread legs. I felt an awesome surge of triumph in me. ‘Gotcha, b*o’!
His tongue, his lips, his fingers, and the feeling of victory sent me over the edge. With a big explosion I came. Even while I jerked and spasmed, he did not stop licking me.
“Stop, stop, stop, b*o!” I shouted, He paused, looked up with a smile.
“You liked it?”
“As always, my son. I am so proud of you!” I was glad that he had not noticed my slip of tongue that could have blown my cover. He quickly got up and exclaimed
“Now it’s your turn mom …. You promised!”
I knew that even in dreams one has to fulfill a promise. Furthermore, I wasn’t sure if he would wake up, if I refused to blow him, so I had to do what I had promised to do.
With a sigh I kneeled down. I honestly like to give blow jobs and I occasionally swallow, but not that time! Sucking my own b*o, who was so nasty to me for so many times was not so easy. I was determined to end this quickly. I spit on it to lubricate it and my hand worked hard and I squeezed as hard as I could when my fist slid over his head. But it wasn’t enough for him.
“Put it in, put it in” he begged me. So, I sighted and opened my mouth. I let my tongue sk** through the groove at the base of his head, which was something he liked. So, I was guided by his moans and groans in my actions. I kept the head at my lips and did not want to take him in deeply. As I had expected, it did not take long for him to reach an orgasm. His balls contracted and just in time I pulled him out of my mouth and directed his tip against my chest. A few seconds later he spurted a whole load onto me while he was clinching the edge of the table behind him in his hands. His head jerked back and forth, and he let out a big, long moan,
He dumped 5,6,7 hot shots of his sticky cum onto my chest, tits and belly. After that he was completely spent. He collapsed besides me and looked at me with a passionate look.
“Mom, you are awesome….” His voice trailed off when he moved his face close to mine. Too late I realized that we was going to give me a big kiss. I had a hard time pushing him away after our lips met.
“Go to bed, son.” I ordered him.
He obeyed and I went to the bathroom to wash off his sticky cum. While the hot water was flowing down my body, I slowly soaped myself off. While I was lost in my thoughts, I played with my sensitive nipples and my still tickling pussy. What had happened? Why did I go all the way and let him suck me and I blew his cock? Actually, it not had been ‘all the way’. I did not fuck him. But the thought that I had stepped over an invisible line, and that I would never be able to make this undone made me uncomfortable and excited at the same time. But what really shocked me was that his actions and words indicated that he had fucked our mother, at least once, in the past. It was hard for me to fall asl**p that night.
The next morning I woke up at the usual time, but to my surprise my b*o was already sitting at the table. He had his head in his hands and only a cup of steaming coffee in front of him. His hair was unkempt and he was breathing very deeply.
“Morning. What’s up, b*o?”
“Non of your business, lil’ s*s.” He grumbled. “Leave me alone!”
Anger welled up in me. How dare he, who had so eagerly sucked my pussy the night before, treat me like that! But then I remembered that it had not been me, it had been his mother - our mother – whom he had licked in his dream.
He sipped a bit of coffee, sighting. I felt so sorry for him. I felt responsible for his bad mood. It was me who had allowed him to continue in his dream. I sat opposite of him, resting my chin on my palms. After a while, he looked up.
“What are you staring at?” he barked.
I decided not to feel intimidated. I decided to bring the topic up.
“I also had a bad dream last night.”
“Non of your business what dream I had. Who do you think you are? My counselor?” after his angry reply he took another sip and disappeared into his room. I heard him shouting some expletives. I sighted, had a toast for breakfast and left the apartment. I did not know, and I also did not care if my b*o would go to university that day.
I took the subway to Ginza and did some window shopping. But instead of wanting to buy a new bag or new shoes, I could only think about my b*****r. This experimental d**g might be killing him. If it could alter his mind so much that he could sl**p-walk, mistake me for my mother, and even have sex with her/me, I had no idea what effect the d**g could have while he was awake.
On the other hand, I found that I was already making plans of what to do with my b*****r that night. If he would be sl**p-walking again, should I make him fuck me for real? The thought of his big cock in my pussy made me wet, and I enjoyed the prospect of having this kind of power over my b*o.
I called a friend, and we had a coffee, but the conversation did not go deep. I was too much lost in my thoughts. Should I go to Roppongi that night and pick up a sexy guy for a one-night-stand? Should I go home and barricade myself in my room? Should I beg my b*o not to take the pills anymore?
Those thoughts were spinning in my head during the day. When I came home in the afternoon, the flat was empty and my b*o was out. I went to his room and saw the bottle with the pills. I still don’t know why, but I made a fateful decision. I opened the box and took one of the pink pills out. It was big, like the bazookas full of antibiotics one has to swallow. I looked at it but I did not see any marks or signs on it. I slipped it in my pocket and left the room.
When I just had finished preparing dinner my b*o came back. He looked weary and tired. He did not speak much during dinner, as usual. After dinner I waited that he would take out a pill and gulp it down, but I waited in vain.
“No pill tonight?”
“None of your business.” Did I ever expect any other answer?
“No ‘But’ lil s*s. The program has been cancelled.” He looked at me. “And no bossing around ‘I told you so’, okay? I am fine, I am fine.” He was very defensive and it would have been a prime opportunity to pay back some of the humiliation he had given me. But I felt pity for him, too.
“So, what happened?” My inquiry made him look for the longest time into my eyes. He sighted.
“Side effects…they found some side effects in some of the test persons….strange things happening to them… night…” and with the familiar rough voice he added “But not with me…okay? Not with me… I am fine, I am fine.” He shouted again.
He looked at me as if he was looking for a confirmation of his statement from me. I did not say anything, so he repeated what he just had explained.
“I am not going to take a pill tonight. I spoke with the guys at the hospital. They called me. There were some complications in other test persons. They forbade me to take even one more pill. Trial finished!”
Not yet, I thought.
“Hey b*o, I am tired and I go to bed now.”
“Good night s*s!”
In my room I popped the pill in secret and I gulped it down with a glass of water. I wanted to experience what he had experienced. I wanted to know how it felt and what made him do what he did. Not even five minutes after I took the pill I started feeling dizzy. Immediately after my head hit the pillow I dozed off. That night I had the strangest dream of all the dreams.
I was at high school. I waited in front of an empty class room. I saw the door and the wall in all rainbow colors and a little blurred. When I opened the door, there was my math teacher. I could not clearly make out his face, but he was unmistaken my math teacher. I adored him. He was such a gifted teacher, and he was handsome, too. His name was Nakamura. Kenji Nakamura. When I saw him alone in the room, I felt the urge to have sex with him. I ran towards him, threw my arms around his neck, even though he resisted at first. My hands pushed his head against mine, so that our lips met. I pushed my tongue into his mouth. I let go of his head and opened his pants. I grabbed his cock. I went down on my knees and sucked him until he was hard. I lifted my skirt. I did not wear any panties. Without letting his cock go, I laid down on one of the school desks and spread my legs as wide as I could. I begged him “Mr. Nakamura, fuck me!” His big body was towering over me. I crossed my legs behind his back so he could not escape and guided his cock into my wet and hot pussy. His rod felt so hot in my burning pussy. He started pumping me hard and fast. I saw the ceiling in all rainbow colors and I heard his hard breathing. “Fuck me, fuck me, fuck me.” I heard me shout. The feeling was awesome. His big cock stretched my pussy to the limit! I lost all sense of time. He thrust his cock deep into me, I screamed after each thrust. Then, he thrust again, and again, and again. I was reaching my orgasm when he came into me. He shot his load into me. He pushed his cock deep into me. I rolled off the desk and collapsed on the floor. I scooped some of his cum from my pussy and swallowed it. When I looked up, there was our school principle. His face was blurred, too, but I knew it was him. His name was Honda. Takeshi Honda. I still had the urge to be fucked. “Mr. Honda, fuck me.” I begged. I was on the floor, and he was already naked. He stepped over me and sat on my tits. He lifted my head with one hand and stuck his limp cock into my mouth. While I sucked him, I fingered my sticky pussy. I needed a hard cock so urgently. It took a while for my tongue to make him hard but I succeeded. With his strong hands he lifted me up and turned me around. He pushed me forward, against the desk. I love to be fucked doggy style and I told him that. “Fuck me from behind, fuck me deep, Mr. Honda!” Again I lost all sense of time. I just heard the slapping of flesh on flesh, and my pussy was burning again. A fire raged in me; a fire so hot and awesome. He fucked me for an hour or so. I screamed, I moaned, I saw dancing rainbows in front of my eyes. And then I came. I came like I had never come before. And then he came, too. But he did not have much cum in him. I was floating on a pink cloud. I heard beautiful music that came from everywhere. Some words penetrated the sound. “Go to bed now”. Of course I obeyed. When I turned around at the door, I saw my b*****r standing there.

The next morning, I felt so miserable. I had a terrible hangover and all I wanted to have for breakfast was a big mug cup full of strong coffee. Somehow I made it to the coffee machine and managed to pour in some water and add coffee grind to the filter. When the smell of coffee filled the room, I sat down. As I was waking up, I remembered my dream. Mr. Nakamura and Mr. Honda, the two teachers at my school that I always had wanted to fuck. I remembered their hard cocks in my burning pussy.
I got up and poured me a coffee. As I watched the steam rise from its black surface, I remembered the pill. And suddenly, the burning sensation between my legs became very real. I reached down and touched my pubic hair that was encrusted with sperm. I really had fucked my teachers. But where were they?
Just at that time, the door opened and someone stepped into the room. That person sat down at the table opposite to me. When I lifted my eyes a bit, I saw a white nondescript bottle in front of me. It was a bottle for medical pills and had the name of a well-known hospital on the label. But instead the name of the d**g and a description about the dose, it only had the following number hand-written on it:
The person shook the bottle and I heard the dry rattling sound of a few large pills bouncing off the walls.
“I counted them, and one is missing.” My b*****r’s voice fully pulled me back into reality.
“Do you realize what you did?” He was very angry with me. “I am responsible for this. They will ask me where the missing pill is.” Since I wasn’t responding he finally shouted “That one pill could have killed you!”
After another sip of the hot liquid I got the strength to reply.
“I just wanted to experience what you had experienced the nights before. I wanted to see what you saw. I wanted to feel what you felt. I wanted to know how it felt……” my voice trailed off.
“How it felt to fuck Nakamura and Honda in a dream? Yeah! Great!” his anger did not subdue. “But it hadn’t been them, it had been me!” I sensed some hurt in his voice.
“And it hadn’t been mom, but me.” I whispered. “I wanted you to understand that the d**g that made you do it…..when I saw you at the table yesterday morning, I could not think about any other way to make you realize that you don’t need to feel ashamed or hurt.”
“Kind of a shock therapy!” He laughed.
I lifted my head and looked him in the eyes. He did not avert my stare and because I could see a new passion in his eyes I asked the fateful question.
“Did you like it?”
The passion in his eyes grew stronger “Tonight it will not be pills, mom or Nakamura….it will be just you and me.”

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