Otoru sat at the dinner table, munching on some take-out as he lazily watched TV. Across from Otoru is his big sister, Yu Takeyama. She had just recently come home from a day out with some friends, noticeably a little on the tipsy side so they might've went to a bar or something. She's just lounging around now, wearing some jeans and a loose white shirt. Otoru had to avoid staring since he could see a bra strap exposed from the shirt's large collar.

In his pocket is a small pouch of a powder that Honda gave Otoru, "sleep medicine" he called it. The plan is to slip some of it into something Yu drinks and do the deed while she's deep asleep. Simple as that, it gave some time to do things...fully. The boy made sure to buy some wipes on the way home for clean up.

Thankfully, his sister did have a glass of water with her as she ate. And when she got up to use the bathroom, Otoru took his chance.

"Hmm. I don't want to knock her out for a like a day or something. Maybe I just put a pinch of it..."

Later that night, the time had come. Otoru'd given it a solid hour before he made his way down the hall, standing outside of his older sister's room. Otoru cracked the door open, peering inside to see if Yu is still awake. Judging by the limp body laying on her bed, he guessed the medication did its job.

Without much time to waste, Otoru opened the door and walked in. The bedroom is a mess, with various objects misplaced around and clothes on the ground. It's not easy to see in the dark but Otoru could swear some of Yu's bra and panties are laid out as well.

Of course the real prize is sitting right on the bed, Yu is sprawled out on the mattress with the blanket kicked to the side. Either the drug worked fast or this is how she normally sleeps because the boy's treated to the sight of his sister in nothing but her underwear. A white set of bras and panties.

She's godly and beautiful, Otoru can already feel his pants tighten a bit at her beauty...and what he was "reluctantly" planning to do. With a nervous gulp, Otoru stepped closer and stood next to the bed. As he continued to stare down, Otoru pulled out his smartphone and unlocked it. The camera was already on as Otoru set it on a nightstand.

With trembling hands, Otoru reached down towards Yu's breasts. He can feel his fingers dance over them, glazing over her silky bra as Otoru looked for the fastener, eventually feeling the plastic in-between her cleavage. As Otoru shot at glance towards Yu to make sure she's still asleep, he fumbled with the bra and finally unclip it. Instantly the bra cups give way and his sister's large breasts bounce free, unrestrained.

They're glorious, large and round. Yu in a bra was one thing, but her bare cleavage is next level. Hurriedly, Otoru took his phone off of the nightstand and snapped a photo...and a few more. Getting it over with, he then texted one of the images over to Honda.

It only took a moment for him to reply with a serious of emotes, conveying his satisfaction. But then he sent a proper text, "NICE DUDE! But Otoru know what's next, right?" He then sent a pair of emojis, an eggplant and sweat droplets. Disgusting, but...

With some hesitation, Otoru put his thumbs into the bands of his pants and underwear, lowering them down briefly and made room for his penis to pop out. It twitched in the coldness of the room, already a little elongated from the excitement of the night so far.

Otoru grasped his hand around his shaft and started to slowly jerk it, causing himself to wince from the sudden rush. But once the boy's manhood started to harden a bit, Otoru paused as a new thought came to mind. As his eyes trailed back to Yu's breasts, the temptation to be more of a shameless pervert clouded his judgement.

Pulling the rest of his pants and underwear off, Otoru only had his shirt on as the boy started to climb into bed. Trying his best to avoid stepping on his sister, Otoru positioned himself with his knees on both sides of her stomach and just barely avoiding directly sitting on her torso. Otoru leaned down and placed his hands directly on Yu's breasts, sinking straight into the large mounds. They're so soft and warm, Otoru just couldn't resist lightly squeezing them but that caused Yu to let out a light moan in her sleep.

Otoru paused a moment to make sure she's still asleep before he moved to his main goal. The boy placed his semi-hard dick into the valley of her cleavage and pushed his big sister's breasts together, sandwiching his cock in an agonizingly blissful embrace. A moan escaped Otoru's own mouth because of it, her tits are the genuine article and Otoru already felt the need to start thrusting his hips.

It started slow, lightly bouncing Yu's mounds in the air as his member slid between them. They're so big that they still envelope Otoru no matter how deep he goes, like a pleasurable vice. But then another idea came to him as the boy thought of a way to make things better, his quirk.

The ability to increase the size of one body part at a time is somewhat useful, given a good situation and this, in a selfish way, seemed like a good one. As Otoru focused, his cock started to grow in size and push against his sister's breasts. Within a few seconds, it had grown over twice it's size and the head poked out of Yu's cleavage. Ready once more, Otoru went back to bucking his hips into Yu's cleavage.

Now at full size, your cock slides all the way through his sister's breasts and it makes all the difference. Pre-cum leaks out and starts to coat her tits, causing Otoru to start slipping through even easier. But as Otoru grew more reckless, the more danger he was putting himself in.

Yu groaned a bit as her eyes began to flutter open, unbeknownst to Otoru as he just focused on his approaching climax. With one big tit-shaking thrust, Otoru orgasmed and released his seed straight into his big sister's face. Pleasure caked his now sweaty body as his first orgasm sent waves of bliss through his mind, coming in bursts as semen pours out of Otoru.

"What the fuck!?"

But this quickly fades as Otoru heard the sound of his sister, causing him to nervously glance down at her. Her glare sends shivers down his spine, even with Otoru's white seed covering her face, hair, and chest.

"Ummm...shit."