Chapter Text
Matthew was sitting on the bus as he looked out the window and smiled seeing the familiar countryside of his hometown as he was happy to be back after being away at college for so long.
He started to think about his little sister Yuzu and thought about how he would now be taking care of her since their parents moved to the city but let Yuzu stay since he could now look after her.
The bus soon stopped as Matthew grabbed his bag and walked off the bus and took a deep breath taking in and remembering the country air as he started heading towards the lake to reunite with his sister.
Matthew soon reached the lake and looked around not seeing his sister but soon a beach ball rolled in front of him as he picked it up and looked to see where it came from as he soon heard someone call out to him and when he looked at who it was he couldn’t believe his eyes.
His little sister ran toward him but she was wearing a white shirt that was soaked as it was completely see through as her body was completely exposed since she wasn’t wearing anything underneath it but was even more surprising were her breasts as they must’ve been a c or d cup.
Yuzu soon stood in front of him and smiled at her older brother “Matthew I’m so happy to see you” she said as he handed her beach ball back to her.
He smiled at her while blushing as he couldn’t help but stare at her exposed breasts and pussy “I’m happy to see you too and it looks like you’ve grown” he said as he tried to look her in the eyes.
She smiled “Yeah I have grown a few inches taller since we’ve last seen each other” she said not realizing he was referring to her breasts.
Matthew continued to blush as he stared at her body “so Yuzu why are you wearing that” he asked her.
“My friends wanted to play at the lake today and I didn’t have a clean swimsuit to wear so I decided to just wear a shirt and is it okay if stay out a little late so I can keep playing with my friends” she asked him.
He smiled at her “of course you can keep playing with them” he told her as she smiled brightly hearing that.
“Thanks so much big brother and I’ll see you at home later” she said as she ran back to her friends while holding the beach ball above her head and while she was running Matthew got a good look at her butt which was nowhere near as big as her breasts but still a nice size for a girl her age.
Matthew walked away and started heading to the school for his interview but on the way there he noticed he had an erection and hoped it would go away or he could hide it.
Matthew soon reached his old school as he walked inside and immediately went to the principals office remembering where it was as he knocked on the door and was soon told to come in.
Matthew walked in the room and saw the principal who was an elderly woman who’s been working here since Matthew was a child and went here.
They started talking and the interview quickly ended as Matthew got the teacher job but they kept talking as they talked about the past as their conversation ended after a while.
Once Matthew left the building it was kind of late as he immediately started heading home and once he got there he went to Yuzu’s room to check on her.
Yuzu was asleep as she was sleeping peacefully as Matthew smiled at her but his eyes quickly moved to her breasts as he still couldn’t believe how big they were.
He continued to stare at them wondering how a girl so young could have breasts big enough that an adult women might be jealous of.
He soon stopped staring as he quickly left her room and went to the kitchen where he saw some food left out for him as he smiled and sat down and started eating as he thought that Yuzu became a better cook while he was gone.
He soon finished eating as he cleaned his dishes and went to bed excited to start his teacher job tomorrow.
He woke up early the next morning and took a quick shower before he made breakfast for himself and Yuzu and once he finished eating he left the house and walked to the school.
Once he reached the school he walked inside as he was excited to teach at the school he used to go to when he was younger as he walked around a bit before going to his classroom.
He soon walked inside but was soon surprised as he saw Yuzu sitting in one of the front row desks.
Matthew looked at his sister as he stood behind his desk and soon noticed her panties were completely visible to him causing him to blush a bit.
He waited until the other students left his classroom before talking to her.
He cleared his throat and looked at her “Listen Yuzu I’m happy that I’m your teacher but while we’re at school I’m just your teacher and not your brother so I won’t give you any special treatment” he told her.
Yuzu nodded and listened as she soon remembered something as she took her shirt off causing her to breasts to bounce a bit as Matthew was blushing.
“Yuzu what are you doing you can’t take your clothes off in public” he said as he looked at her breasts.
Yuzu looked at him as she pulled her skirt down as she was now only in her panties “I have gym class and I don’t want to be late and it’s okay since we’re siblings” she said as she put on her gym shorts and shirt.
Matthew looked at her as her gym outfit clung to her body nicely “well try to remember not to do it again” he told her.
“Okay I’ll remember next time” she said as she left the classroom to go to gym class.
Matthew didn’t have a class to teach so he decided to keep an eye on Yuzu during gym class and he noticed that while she was jogging her breasts kept bouncing as he stared at them during her entire gym class.
When she finished she ran over to him “Hey Matthew did you see how fast I was running” she asked him.
”Yes I did and you’ve gotten more athletic since the last time I saw you” he said smiling at her.
She smiled “Thanks but I’m all sweaty” she said as she lifted up her shirt to wipe her face as her breasts were now exposed again.
Matthew blushed and stared as he looked around to make sure no one else saw her as she soon put her shirt down “Is something wrong” she asked.
He looked back at her “no nothings wrong but next time use a towel or a rag to wipe your face and not your shirt” he told her.
“Okay I’ll try to remember” she said as she walked off to her next class as he then followed her.
Throughout the rest of the school day Yuzu continued to accidentally show off her body to her brother and now she was helping clean as she was crouched down putting a rag in a bucket while her panties were showing a bit and a few of the bottom buttons her shirt somehow got undone showing the bottom part of her breasts a bit.
Yuzu looked at Matthew and still had a smile on her face “you’re a great teacher Matthew” she said.
He smiled “Thanks” he said as he watched her get on her hands and knees as she started washing the floor while her panties were completely exposed.
Matthew had trouble controlling himself as he kept getting turned on whenever he saw his little sister as he tried to hold it for the rest of the school day.
Eventually the school day ended as Matthew quickly went behind the school not noticing that Yuzu watched him walk away quickly.
Once he was behind the school he unzipped his pants letting out his fully erect cock as he started to stroke himself while thinking of Yuzu.
Yuzu walked behind the school and saw her brother and smiled as she tackled him from behind “I found you” she said as he fell onto his back with his huge cock completely visible to her.
Yuzu soon saw his cock and gasped “is that your cock it’s huge” she said as he didn’t hear that last part as he imagined himself being taken away by the police and going to jail but was soon snapped out of it when he felt her soft hand touch his cock.
She smiled at him “why is it so big and hard were you thinking naughty thoughts and touching yourself cause if you want I can help you cum” she said.
Matthew couldn’t believe what he was hearing as his little sister just said something so naughty.
He was about to say something to her but stopped when she slowly licked the tip of his cock as she then sped up her licking before putting the tip in her mouth.
Matthew couldn’t help himself as he let out a moan and started thinking “how does she know how to do this did she find dad’s hidden magazines or did she see a video online” he thought to himself.
Yuzu sucked on his cock as she started taking more of it in her mouth as she soon got most of it in her mouth.
He let out another moan “Yuzu what are you doing you need to stop” he told her.
Yuzu looked at him before taking his cock out of her mouth “you don’t want me to use my mouth then okay I’ll use something else” she said as she pulled down her skirt before taking off her panties as he could see her wet pussy.
She soon stood in front of him as she spread her pussy and more of her shirt buttons were undone completely exposing her breasts “I will use my pussy to make you cum” she said as she slowly moved down aligning her pussy with the tip of his cock.
Matthew looked at her “Wait Yuzu why are you doing this” he asked her.
She looked at him and smiled “It’s because I love you big brother and I want you to use my body to make yourself feel good” she said as the tip went inside of her.
Matthew gasped and moaned as he watched Yuzu slowly slide down on his cock and he could tell from her face and how tight she was that she was still a virgin.
It didn’t take long until Yuzu slid all the way down to the base of his cock as she was moaning “I can feel you all the way inside me” she said while moaning.
He moaned and looked at her “Yuzu this is wrong we shouldn’t be doing this” he told her.
Yuzu looked at him and got a smug look on her face “so do you want me to take your cock out of me” she said as she slowly lifted herself up his cock.
He moaned and before the tip left her pussy he started speaking “no don’t I want you to put it back in” he said as she immediately slammed back down to the base of his cock.
She soon started bouncing as they both moaned “oh god I’m having sex with my little sister this is so wrong but it feels so good and she is so tight” he thought to himself.
He soon reached up and grabbed her hive breasts and started thinking that he didn’t care how wrong this was.
Yuzu moaned as she kept bouncing “do you like my boobs they’re really big aren’t they” she asked him.
He started rubbing her breasts “they’re huge and feel nice and they are so perfect” he said.
Yuzu started to bounce a little faster as he kept moaning “her body is small but her breasts are huge” he thought to himself.
Yuzu smiled and leaned on him “sex feels amazing and are you going to cum inside of me” she asked.
He was surprised by this question “do you want me to cum inside you” he asked as he thought about how great she was at this and how tight her pussy was as he felt he couldn’t last much longer.
Soon he could feel he was about to cum “Yuzu I’m going to cum” he said as he shot a huge load of cum into her pussy.
She moaned out loudly “I can feel it and it feels so hot” she said as he soon finished cumming.
the two of them panted a bit “Matthew did you enjoy that” she asked him.
He looked her in the eyes “Yes I loved it but we shouldn’t have done that” he told her.
Yuzu quickly asked him why “It’s because I’m your older brother and also you’re way too young to have sex” he said.
”But Matthew you’re the only one I want to do this with and aren’t you only supposed to do it with someone you love and I love you” she said smiling at him.
He blushed “Yes you should only do it with someone you love but still we shouldn’t” he said.
“Big brother I really liked doing it with and it felt amazing for me too and I hope I get to cum next time too” she said as she slowly slid off his cock.
He was a bit surprised by that “oh I’m sorry you didn’t get to cum” he said but she wasn’t paying attention as she got distracted by a plane in the sky she thought might’ve been a UFO.
Yuzu soon fully stood up as one of her breasts was still out and she started wiping her pussy with a rag “We should probably head home now and get started with dinner cause I’m getting hungry from what we did and let’s do it again after dinner” she said.
He was surprised “wait you want to do it again” he asked her as he zipped his pants up putting away his cock.
She smiled at him “Of course it was really fun and we should do it a lot more times” she said as the two of them walked home together.
After that moment the two of them continued to have sex as shortly after dinner Matthew was sitting in his chair with his sister bouncing on his lap “Do you like my body cause I love how your cock feels inside of me” she said.
”Yes I love your body” he said as he thought about how wrong this was but he didn’t care as he saw how much she enjoyed it and how good it felt for him as he soon came inside of her.
The next day during their break he took Yuzu to one of the supply sheds after she finished swimming as he pressed her against the wall and thrusted into her.
”Matthew do you think my body is too small” she asked him while moaning.
He continued to thrust inside of her “no I love how small your body is except for your huge breasts” he said.
”Well what about my breasts do you like that they’re big” she asked him.
He sped up his thrusts “Yes I think it’s the perfect combination and I wouldn’t want you to be any other way” he said as he could feel himself getting close.
Matthew had soon realized he had become addicted to sex with Yuzu as he would have sex with her whenever he got the opportunity and didn’t care where it was as he thought her body was made for sex and wanted to enjoy it as much as he can.
It didn’t take long until Matthew no longer started to care how wrong it was that he was having sex with his underage sister as he only wanted to pleasure her and it helped that she acted like this was a normal thing.
One day while at the river they got an idea to try it out in the open as he sat on a rock as she immediately got on his lap putting his cock inside her as they then had a make out session while having sex out in the open.
Eventually they started to do it in more public places when no one was around like on the road under a bridge or at a bus stop with Yuzu giving him a blowjob as he came all over her face and in her mouth as she enjoyed every second of it.
There were times Matthew questioned what they were doing thinking about how if they ever got caught they could get in serious trouble but he tried to convince himself it was okay since she wanted it.
He was soon snapped out of his thoughts when Yuzu walked into his room wanting his opinion on her new outfit as it was a tank top that could barely hide her breasts and had the word rabbit written on the top and a skirt with a bunny on the side.
He smiled at her “yeah it looks great on you and you look great in anything” he told her.
She smiled “thanks and I knew you would like it when I bought which makes me happy but I bet you like it even more when I’m not wearing anything right” she asked as she moved her top to the side letting out one of her breasts and then lifting up her skirt revealing she wasn’t wearing any panties.
Matthew stared at her thinking he couldn’t resist her as they both immediately took off all of her clothing as she lied down on his bed with her legs spread wide as she looked at his cock “wow you got so big and hard so fast and hurry up and put it inside me cause I love how it feels” she said.
He smiled and immediately did what she asked as he thrusted his cock into her pussy causing her to moan “your cock is so big and it keeps stretching my pussy whenever we do it” she said while moaning.
He started thrusting as he grabbed her hips “do you like having sex” he asked her.
She moaned louder “yes I love having sex with you it’s the best feeling in the world and I love how good it makes my pussy feel” she said.
He sped up his thrusts as he leaned down to suck on her breasts making her moan more.
After a while he got an idea as he pulled away from her breasts “Yuzu maybe we should stop” he said as he started to slowly pull out.
“Please don’t tease me put it back in I want you to pound my pussy and not to stop” she said as he smiled and thrusted back into her.
He soon lied down next to her and held up her leg as he continued to thrust inside of her as he thought about how her body was made specifically for him.
He sped up his thrusts even more as he grabbed and squeezed her breasts while listening to her say fuck me over and over again.
He lied back on top of her “Yuzu I love you” he told her as she immediately said that she loved him too as they shared a passionate kiss while he kept thrusting.
After a while he could feel himself getting close as he pulled away from the kiss “I’m going to cum” he told her while moaning.
She moaned and smiled “cum inside of me I want you to fill my womb” she told him.
Matthew was a bit confused as she never said that before “why do you want me to fill your womb” he asked her as he kept thrusting as he could feel some cum start to leak out.
She moaned louder “it’s because I started my period the other day and I want to have a baby with you” she said.
He was surprised by this but he couldn’t stop as he soon thrusted one last time before they both came as he started cumming inside of her filling her to the brim with his cum.
They both panted “I can feel your cum filling my womb and it’s so warm” she said panting.
He looked down at her and wrapped his arms around her with his cock still inside her “Yuzu do you really want to have my baby” he asked her.
She smiled and hugged him “of course I love you and I only want to make babies with you” she said as he smiled and told her ok.
After some time the two of them had gotten dressed as Yuzu was excited “we finally had sex as adults” she said jumping up and down a bit.
He smiled at her “but we’ve been having sex every day” he told her.
She looked at him and pouted a bit “but this is different I can pregnant now and I’m going to have your baby” she said excitedly as he smiled and laughed a bit thinking she still acted like a kid at times.
”Calm down and besides you might not be pregnant and it’s possible you’re not fertile so it might not happen” he told her.
She got a bit angry “that’s not true I’m probably super fertile and I’m going to be pregnant” she said.
He continued to smile “Okay fine you are going to be pregnant” he told her as she got a confident smile on her face.
”That’s right I am going to be pregnant with your baby” she said as her expression soon changed as she had a cute smile on her face “hey Matthew let’s have sex again right now” she said.
He smiled at her “Sure” he said as he thought about how immature she acted but her body was so mature so she might get pregnant as they soon started to have sex again.