Katsuki and Izuku, age four, sat silently on Katsuki's bed at his house. Izuku was quieter than normal. Normally, he would've been talking Katsuki's ears off by now, but he hasn't said anything since playing with the extras at the park. It started off normally. They were playing the usual heroes vs. villains when Deku, the civilian- he's always been the civilian, it was unfair-, found something weird at their "base." It was a thin manga with several missing pages. On the cover was a well endowed woman with a man standing behind her, arms wrapped around the woman. With nothing much to do, he read the manga, only understanding parts of it due to his lack of vocabulary. He was only four years old after all.
One of the children noticed how quiet their civilian was and went to take a look. "Hey, look! Deku's reading a manga!" He points out. Deku didn't pay him any mind. He was invested in the love story he was reading. The drawings were so cool and pretty. The page he's reading was set in the bedroom. It was saying something about being ready? He didn't really know.
At the child's remark, everyone else stopped playing and gathered at the base. Katsuki, the leader, marched in and plopped himself right next to Deku. He grabbed the manga off of his hands and started reading it too.
"Kacchan!" Izuku immediately tried to grab the manga back. "I was reading that!"
Katsuki chose to ignore him and read some of the words out loud. " 'Are you sure you want to have s-se?' What's this word?!"
A boy behind them answered the question, "Sex! My mom told me about what that is!" The kids around them muttered in confusion. Some expressed that they've never heard of it before. Then, they all started to ask what sex was. He answered, "She said it's something you do with your special person!" But that was all he knew. Everyone was unsatisfied with the answer, so they urged Katsuki to keep reading.
Katsuki obliged and read aloud, " 'Yes, I want to lose my virginity to you.' " Even more confusion spread amongst the group. Katsuki thought to himself what the statement meant and came up with something. "I think "virginity" means they haven't had sex before so losing it means that they will!" He concluded proudly. They agreed with his statement, said that it made sense.
Deku nodded along and muttered his usual, "Kacchan is amazing."
Katsuki kept reading, "The guy nods and then he starts kissing the girl!" He turned the page and it was more kissing, he described to the group. Izuku sees the illustrations on the page beside Katsuki. Katsuki turned to the other page only to find it empty. "It stopped."
"That means kissing is sex!" Someone exclaimed.
Another one disagreed, "No it isn't! My brother told me kissing is kissing." They all believed the boy. Everyone, then, started to think about what sex actually meant. Suddenly, the child that was told about sex, vaguely, by his mom, snapped his fingers.
"I know! It is kissing but it's only sex if they kiss on the bed!"
Katsuki contemplated it, looked back at the pictures, and slapped the guys back. "Good job! That's definitely what sex is!" The boy brightened at their leader's praise. It's not often Katsuki praises someone after all.
After all that commotion, they had to go home. Now we're back at the Bakugou residence, Katsuki's bedroom, still silent, still awkward. Katsuki's getting a little annoyed. He barked, "Deku! Why are you being so quiet?!"
Izuku, who was lost in thought, jumped back to reality at his voice. "A-ah, it's nothing Kacchan! Let's go and-"
"That's bullshit!" Katsuki interrupted. "You're all spacey and shit, you're thinking about something aren't you?" He deduced, eyes pointed accusedly at Deku's shifty eyes.
"Of course, Kacchan's amazing after all..." Izuku bit his lip in nervousness. He sighed defeatedly, knowing that Kacchan wouldn't let it go until he told him. "I was just thinking about the s-sex thing..."
"What about it?" Katsuki scoffed at the stutter. It turned out it wasn't anything important.
"Well... Sora said that you do s-sex with your special person..." Izuku stumbled at the word "sex" again. He started blushing at the thought. Katsuki grunted an agreement and urged Deku to keep going. "U-um... I have a special person so does that mean I have to do it too? Like the people in the manga?"
The words registered a little late in Katsuki's little brain. After it did, though, it echoed in his mind repeatedly. Deku has a special person. Deku has a special person. Deku has a special person. Who is it? Is it someone we know? Is it me? Frustrated by his thoughts, he demanded, "Who's your special person?!"
Deku, the stupid little dweeb, turned even redder than he already was. He didn't answer Katsuki, however. Agitated, Katsuki spoke up again, "Spit it out!" It better be me, he thought.
"Kacchan!" Izuku blurted out from the pressure. "Kacchan is my special person!" He gasped and covered his mouth in surprise. Katsuki stood on his bed triumphantly.
"Hah! I knew it was me!"
"You did?" Izuku startled at the response. Katsuki let out sparks of celebration. Izuku felt a little brave and asked Katsuki who his special person was. Katsuki, confident as usual, answered, to Izuku's disappointment,
"No one!"
Izuku, saddened by the statement, muttered, "O-oh, okay, Kacchan." He curled himself back up into a ball of despair. Katsuki noticed the lack of enthusiasm at Deku's response and looked down to see his friend's face two seconds away from crying. He groaned inwardly. Stupid, useless Deku...
"Fine, I'll have sex with you, Deku!" Katsuki declared, all hero-like, as if he didn't say something completely inappropriate. Not that he knew that. Good thing the neighbors couldn't hear anything and his parents weren't home.
Izuku lifted his head up from his lap and stared at Katsuki with awe, "Really?!" His heartbeat picked up and he felt his smile spread wider across his face.
"Of course! Since no one will have sex with you, I'll do it!" Katsuki predetermined for him. His insult flew right over Izuku's head. He was very excited that he'll lose his virginity (did he say it right?) to his special person! It was awkward for a moment before Katsuki kneeled, eye-level in front of Deku. Deku's eyes were already closed in anticipation. Katsuki flashes back to the images in the manga. He moves closer to Deku, closer than he's ever been, and pressed his lips gently on Deku's lips.
It was warm. Both of their lips were soft, with Deku's a little chapped, but the feeling was nice. Deku flashes back to the manga's images and he opens his mouth slightly. Katsuki feels the action and does the same. Their lips slot together and they press harder against each other. After a few seconds, they separated. They both breathe hard with blushes on their cheeks. A few moments passed and Katsuki admitted, "It was good."
"Mn." Izuku agreed. Then, as children do, they moved on and started to play with All Might figures.
It was the last time sex and kissing ever passed their brains. The next time they encountered anything of the like was in their 3rd year of UA...
