Chapter Text
"Satoshi! Come here, quick!!"
The young boy climbed up the stairs and hurriedly entered his sister's room.
"Nee-chan!" he shouted in a panic. "What's the matter?!"
As soon as Satoshi took even a single glance at the room, he could tell that there was no need to worry. Ritsu didn't often call out to him like that, so he was immediately overcome with worry; he thought that maybe she had had an accident or something but she looked just as carefree as ever. Having said that, she was wearing a rather peculiar outfit. It didn't take long for Satoshi to realise that it was the uniform of Sakuragaoka Girls' School, where Ritsu was going to start attending in the next school year.
"Well?" asked Ritsu.
Satoshi seemed perplexed.
"Well... what?" he asked.
Ritsu pouted, as if it should have been immediately obvious to Satoshi what she was referring to.
"What do you think? I look so cute, right?!"
Inadvertedly, Satoshi grimaced a little hearing his tomboy sister speak those words.
"Since when have you cared about looking cute?" was his eventual response.
Ritsu fell to the ground in a highly dramatic manner. She slumped her head down defeated.
"It's my high school debut, you know! I'm only ever gonna get one so I absolutely have to make it count!"
"Is that so..."
Satoshi's response was deadpan, which annoyed Ritsu. As her younger brother turned to leave, she jumped up onto her feet and rushed towards him with all the speed of a bullet from a gun. She tightly gripped his shoulders and spun him as if he were a top. The young boy, surprised by his sister's sudden action, started to feel dizzy as he span around unable to regain his footing. Ritsu then grabbed the top of his arm and brought him to a sharp stop. He was now staring straight at her, with her arm still gripping his own.
"Okay, okay," said Satoshi, as he started to regain his sense of balance. "I get it, sorry for being so dismissive."
"As you should be!" snapped Ritsu, clearly at least a little bit genuinely annoyed.
Standing so close to Ritsu, Satoshi got the uncanny feeling that something was off. He hadn't noticed it when she was across the room, but with so little space between them he could not avoid the fresh, almost floral, scent emanating from her.
"Hey," he said. "Are you wearing perfume?"
Ritsu's cheeks changed hue abruptly, and she took a few steps back from the boy. More embarassed by the second, she turned her head and looked away from Satoshi at something - anything - else. She was searching the depths of her mind to come up with an excuse or response, but every second her mind spend blanking the more flush her face became.
"S-Shut up..." is the phrase she eventually settled on, causing a mischevious grin to form on her brother's face.
"Oh? What's this?" teased Satoshi. "I didn't know you could get embarassed like this."
"Enough!" she shouted somewhat forcefully, at least enough to stop Satoshi from continuing. "Good grief! All you needed to do was say I looked cute and then I would've just let you go!"
"Well," started Satoshi, turning away and bringing his index finger up to his cheek. "I guess you do a little. Is that good enough?"
As if a switch had been flipped in her head, Ritsu's mood completely shifted and she was positively brimming with energy. She tilted her head down slightly, cutely holding a finger up to her face and flashing a cheeky smirk.
"I knew it!"
She hopped up onto one foot and stretched out her arms. She raised herself onto her toes and performed a cute twirl. As she did, Satoshi couldn't help but direct his attention to the quickly rising piece of fabric around the top of her thighs. It was only natural, to Satoshi at least, that his gaze be directed at the part of the outfit that was moving the most. As his sister's white cotton panties flashed into his vision, Satoshi quickly jerked his head to the side and stared at a particularly interesting part of Ritsu's floor. Once she had finished her motion she noticed Satoshi had his gaze fixed on the floor. His cheeks were flushed and his head tilted unnaturally.
"What's up Satoshi?" she asked the boy.
"D-Don't you think it's... a little too short...?" came his response.
Ritsu slightly cocked her head, puzzled.
"Your skirt..."
Within moments, Ritsu made the connection in her mind. Almost instinctively, she grabbed the hem of her skirt with both hands and pulled it down, even though by now the moment had passed. Ritsu knew it futile, but her reaction was instinctive. Her face, too, began to shift back towards the reddish shades it had shown previously in their conversation.
"W-What does it m-matter to you?!" she asked, flustered.
"Aren't you worried that people will see?"
"Well..." she started. "It probably won't matter, right? I mean, Sakuragaoka is a girls' school... so..."
"What about Akiyama-san?"
"Huh? Mio? What about her?"
Ritsu seemed genuinely confused.
"I thought you two were... y'know..."
Again, Ritsu connected the dots in her mind as she followed the implications of Satoshi's statement.
"Whoa, whoa, whoa!" interrupted Ritsu. "I mean, yeah, we're good friends but I'm not gay!"
"You're not?" responded Satoshi, incredulously.
"No! Whatever gave you that idea?!"
"I don't know. I just kinda... assumed."
After one of the more awkward encounters that the Tainaka siblings had ever had to navigate, Satoshi said his farewell to Ritsu and returned downstairs for the remainder of the evening.
Satoshi could not find an explanation as to why he kept thinking back to his sister during the night. The mood of the interaction, perhaps? Although that certainly wouldn't explain why his mind kept presenting him with the memories of catching a glimpse at his sister's underwear. Obviously, it had not been the first time that Satoshi had seen Ritsu's panties. In fact, being siblings, it was a common - almost trivial - occurance. Why then couldn't he shake this particular incident from his consciousness? The sight of her in that high school uniform... how he had said she was cute, however begrudging the admission may have been. The memory of her perfume invaded his thoughts, confusing him further. Had he ever really seen his sister as a girl before? She had always been a bit of a tomboy. Perhaps that was why he was so fixated on the events of that evening. Perhaps that was why he couldn't stop thinking about her. Perhaps that was why he had his hand wrapped around his dick, stroking himself to the memory of those events...
Morning came around six hours after Satoshi, and he woke up in a groggy daze. He sat up in his bed and yawned. As soon as he closed his eyes, his mind immediately wandered to thinking about Ritsu again. His eyes snapped open and he straightened his back fully, as if being instructed by an army general. He could feel blood rushing to his cheeks and various other places. But before he could relieve himself, there was knocking sound at his bedroom door.
"Satoshi?" Ritsu said from behind his door.
"Y-Yeah?" responded Satoshi, for some reason feeling slightly nervous.
Ritsu opened the door. She was no longer in the Sakuragaoka school uniform from the previous night, instead donning a regular white T-shite and a skinny-fitting pair of jeans. She was wearing her now-iconic headband too. Satoshi made the assumption that she was going out to meet someone.
"Could I ask you for a favor?"
"What do you want?"
"Haha... well, you see..." started Ritsu in an overly cutesy voice. "Mio-chan's coming over later today aaaaand I was wondering if you could help me clean my roo-"
"No chance," interrupted Satoshi.
Ritsu puffed her cheeks indignantly.
"You didn't let me finish!"
Satoshi rolled his eyes, yet made no further attempt to stop her from speaking.
"*ahem* Yes, so anyway..." Ritsu continued. "I've cleaned most of it up! Just a few bits of trash need to be cleared up, that's all! I'll pay you!"
Satoshi considered for a moment.
"When are you meeting her?"
Ritsu started scratching the back of her head nervously.
"I was supposed to meet her around ten minutes ago..." she replied. "I just got a call from her asking where I am. You know what she's like..."
"Hmm..."
Satoshi pondered for a moment.
"1500 yen."
"Y-You're not serious, right?"
"Fine, I guess you'll just have to clean it yourself."
"Okay fine, fine! 1500 yen, right?"
Ritsu grabbed her purse from her pocket and rifled through it. She pulled out a handful of coins and passed them to Satoshi, who chuckled a little under his breath.
"There! Happy now?"
"Incredibly. Thanks nee-chan!"
"We'll be back in around half an hour. Make sure you clean up, okay?!"
With that, Ritsu turned on her heel and darted down the stairs without even bothering to close Satoshi's door first. The young boy sighed and got himself out of bed.
After around twenty minutes, the cleaning was pretty much done. Satoshi had barely filled a single trash bag. Taking a quick glance around the room, Satoshi noticed a couple more empty water bottles near Ritsu's drawers. They seemed to be the last bits that needed removing, so Satoshi quickly headed over there. He bent down to pick up the water bottle, steadying himself with his free hand. However, as he made to raise himself back up, he applied a little bit too much pressure to the front of the drawers. They started to lean over and a couple of the drawers fell open through gravity. Luckily, Satoshi managed to stablise both himself and the furniture before either one completely toppled over. He stood himself up and raised the chest of drawers up with him.
He of course did not mean to look inside - after all this was his sister's private space. However, after catching a glimpse of the top drawer's contents he became somewhat intrigued. Tens of pairs of panties lined the inside of the drawer, a number of them similar to the ones he accidentally caught her wearing the previous night. This would have been plenty for Satoshi, especially in his current state of mind, however what was more intriguing was the object on top of them. Satoshi certainly hadn't seen an object like it before. It looked, for all intents and purposes, like a microphone, albeit with a few notable differences. For starters, the top of the device did not have the characteristic metal mesh of a dynamic microphone, but instead had a more rubbery material at its head. There seemed to be an on-off switch on the side, whereas most microphones that Satoshi had seen had their switch on the bottom. Ritsu had always been a keen musician and had mentioned starting a band before. Could this device have had something to do with that?
Without really thinking about it, Satoshi reached in and grabbed the device. He wondered what would happen if he turned it on. Cautiously, he flipped the switch on the side. His surprise when the device starting vibrating in his hand almost made him drop it. Maybe it was a massager of some kind? A low hum emanated from the device as it pulsed. Satoshi wondered where his sister had purchased it and what she used it for. As far as he knew, she didn't experience any joint pain or anything. He wondered where Ritsu even got this thing. As he was about to switch the device off and return it to its proper location, he froze.
When Satoshi turned around, he saw that the door to his sister's room was wide open and looking directly at him from the space created by the ajar door... was Ritsu's friend Mio.
The two locked eyes for a moment. The device was still in Satoshi's hands vibrating with reckless abandon. The low hum it generated seemed to be ten times louder in the awkward silence as the two stared at each other not knowing what to say. As if waking from a trance, Satoshi shook his head, quickly switched the device off, and returned it to his sister's underwear drawer. Rising as fast as he could to his feet, trash bag in hand, he bowed curteously to Mio, whose face had turned a bright red. Trying not to meet her eyes, he said "sorry for intruding" and without even waiting for a reply, walked past her out of his sister's room.
He quickly descended the stairs, almost losing his footing a couple of times. He took the trash he was holding to the receptacle outside his house and launched it in unthinkingly. His mind was flooded with thoughts and questions. What if Mio thought he was just a pervert taking advantage of his sister's absence to rifle through her underwear? Why were her eyes so focused on the device that Satoshi was holding? What was even going on with him in the first place? He'd never even thought about Ritsu in that way before... but now? He couldn't stop thinking about her. Her clothes, her room, her face, her panties... he even caught himself checking out her butt as she turned to leave his room that very morning. He didn't know what to do!
He took a couple of deep breaths, and told himself to calm down. He just needed to get his mind off things. Yeah, that was it. Maybe he'd go and meet up with his friends from school and play soccer or something. And that's exactly what he did. He headed round to his friends' houses and gathered them all up to go and play soccer at the park. Blowing off steam like this was something he needed to do a little more often, he thought.
After an active day of soccer, Satoshi waved his friends off and headed home. Although it wasn't too late, the skies were darkening rapidly, as Satoshi would expect at this time of year. A chill ran through his body as the temperature dropped a little, and he tried to hurry his way home a little quicker.
Once he arrived, he reached out to grab the door handle. However, the door ended up opening from the other side. Stood before him were Mio and Ritsu. Once Mio had processed that Satoshi was standing before him, she buried the lower half of her face into her scarf and tried to avoid making eye contact with him. Satoshi looked away as well. Following this awkward exchange, Mio walked quickly past Satoshi and off down the street. After Mio had passed, Satoshi stepped forward but Ritsu blocked his path. He looked up at her and she narrowed her gaze as if evaluating him. Satoshi looked away.
"Guilty!" she said.
Surprised, and a little defensive, Satoshi retorted to her accusation.
"Huh? What do you mean by that?!" he asked, knowing exactly what she meant.
"Don't think you can hide it! Mio-chan told me the whole thing!"
"She probably... made it up!"
Even Satoshi thought that wasn't very believable, and the cadence of his voice betrayed this to Ritsu as well.
"Don't be an idiot!" she said forcefully. "Now you'd better tell me, why were you messing around with my vibrator?!"
At that moment, a penny dropped in Satoshi's mind. Of course, he sort of knew what a vibrator was, but he had never seen one in person before. As if making the connection in real-time, Satoshi spoke quietly to himself.
"Oh, so that's what it was..."
Ritsu was red with rage and embarassment and gave Satoshi a chop to the top of the head in her anger.
"Ow!"
"Serves you right for going through my private stuff!"
"I didn't do it on purpose, nee-chan! It was going to fall over-!"
"Stop making excuses!" she responded. "If you're gonna be a pervert at least have the decency to be honest about it!"
Ritsu stormed into the house, leaving the door wide open behind her.
The rest of the evening was as awkward as anyone would have expected after such an altercation. Ritsu and Satoshi didn't even speak for the remainder of the night.
As Satoshi settled into bed for the evening, his mind went back to what his sister had said. He realised he was probably in the wrong. He really should have apologised to her. Satoshi checked the alarm clock on his bedside table. It was 11:30pm. Perhaps Ritsu was still awake... he might have been able to apologise there and then. Quietly, Satoshi slipped out from under the covers and slid on his slippers. He tip-toed down the corridor towards his sister's room being careful not to make too much noise in case she was still asleep. As he approached, he noticed that her bedroom light was still on. He relaxed his stance a little upon seeing this, but he remained as quiet as he could. After all, she could be in the middle of something.
And in the middle of something she certainly was. That much was clear as soon as Satoshi stood in front of her bedroom door. It was left slightly ajar, as she had left many doors that day, and through its gap Satoshi could hear a familiar low buzzing sound.
'No way...' he thought to himself.
He knew it wasn't a good thing to do... but he couldn't help himself. He peeked through the slightly open door and saw Ritsu lying down on her bed. She was holding the vibrator in her right hand, and she was pressing it firmly onto her entrance. Satoshi's eyes widened. Her jeans were still half-worn, lying about halfway down her legs. Her panties, too, had been lowered and Satoshi was able to directly see his sister's pussy. Her other hand was buried underneath her T-shirt, and it looked to the best of Satoshi's guesses like she was fondling her breasts. She was covered in sweat and she shifted the vibrator around her sensitive area. Satoshi was able to see her facial expression change with every movement of her hand. Her eyes were closed tightly and her mouth alternated between being fully agape and struggling to remain shut. She wriggled and writhed in her bed as the device in her hand sent shockwaves of pleasure pulsating through her body, her knees bending and back arching with each stimulating pulse.
Satoshi had already reached for his dick at this point, and started tugging away as he watched his sister through the gap in her door. Mere days ago he had been unable to see his sister as a woman, and yet now he couldn't stop thinking about her. He kept stroking his cock whilst keeping his eyes squarely focused on her. She was clearly close to climaxing, that much was certain from how frantic her breathing had become. She pressed the vibrator squarely onto her clit and sharply inhaled at the intense pleasure. She applied intermittent pressure to the area in bursts of a few seconds at a time. She could not stop the soft moans escaping in hushed breaths from her lips. This caused her voyeuristic little brother to stroke himself more rapidly. The sheer intensity of his pleasure meant that he couldn't even keep his eyes open as he stroked and pumped his dick. Suddenly, the wave of pleasure that had been building within Ritsu overwhelmed her, and she let out a sharp moan. She had been trying to keep quiet, but she simply couldn't help herself.
As her climax receeded, she slowly opened her eyes in a dreamlike stupor. She realised her bedroom light was still on... but more than that. She could hear a sound from outside her bedroom door. It was only a faint sound; as if someone was rubbing their hands together. She also noticed a wavering shadow close-by to her door. She could not immediately tell what these two related events were. Ritsu stood from the bed, pulling up her panties and jeans. She walked slowly towards her bedroom door. As she approached, she noticed another sound.
Hah... hah... nee-chan... nee-chan...
It was only faint, and she was still coming down from her climax, so she did not connect the dots right away. However, by the time she swung the door aside and noticed her little brother tugging his cock in the middle of the hallway, she only had one thing to say.
"Satoshi?!"
As Ritsu said this, Satoshi's eyes shot open and from the end of his dick emerged ropes of warm cum, shooting through the air and landing straight on Ritsu's jeans and T-shirt. He kept ejaculating his load all over her, and all Ritsu could do was stand there completely motionless.
...
Silence.
Ritsu met Satoshi's gaze.
As if becoming aware of his surroundings for the first time, Satoshi's face shifted from an expression of ecstacy to one of despair. How was he gonna get out of this one...?