Properly Educating the Men of the Reversed World (4)
Seiji reflected. Peering through the crack in the door at his sister's naked form bathed in light, he tried to summon memories of the past through her.
"Ellerie collerie~ Seiji's such a weakling~"
"Hey, I'm not a weakling!"
"What do you mean, not? Without your big sis, you're just a puny little runt who can't do a damn thing~"
A frail, incompetent boy. That's how he had been defined back then, and it was only natural that rough-and-tumble girls would tease him endlessly. Meanwhile, the boys his age envied the attention he got and busied themselves gossiping jealously about his looks.
"Getting attention from girls again."
"So what if he's pretty?"
"Fucking annoying. Total mood-killer."
Not a single kid among his peers welcomed him. That reality was too harsh for a young, fragile boy to endure, and Seiji's eyes never went a day without tears.
"Sob, Mommy, Daddy... "
"Pfft, crying again."
"Seiji's a crybaby dummy~"
Even the sobs born of his misery became fodder for mockery, trapping him in a vicious cycle. But that vicious pattern didn't repeat forever. Even in an environment too brutal for a child to bear, there was always at least one ally by his side.
"Hey, you lot! Bullying Seiji again?"
"Gah, gorilla alert! Run for it!"
"Who're you calling a gorilla! Hey! Don't you run away from me!?"
Senya. His one and only sister. Unlike Seiji, she had a sturdy body and spirit, and whenever she showed up, the neighborhood kids would flee in terror. In the quiet aftermath, Senya always comforted him.
"Seiji, you okay?"
"Ugh, Sis, Siiiis..."
"Aigoo, what can you do with boys like this? My little Seiji's such a crybaby."
She wiped his tears, stroked his hair, and gently scolded him. But even with her care, Seiji couldn't stop crying easily. He knew that even if the kids backed off now, it would all repeat later.
"Am I... the problem?"
"What do you mean, problem?"
"Because I was born weak... That's why they bully me, right? Is crying all the time what's wrong?"
He hadn't chosen to be born this frail boy. Was simply being born such a sin? Looking back now, it was heartbreaking that he'd harbored such self-loathing from such a young age, but even in his negativity, his sister never withdrew her kindness.
"Seiji, you always worry about useless stuff."
"Useless...?"
"No one in the world can call being born a mistake, Seiji. People are just born different and grow up different. Being different isn't wrong."
Seiji remembered it well. The gentle whisper of advice she'd given him that day. And the rough touch of her hand stroking his head.
"Boys like you are naturally weak, Seiji. But as a boy, you're also born with a delicate, thoughtful heart. Everyone teases you for being weak, but to me, that weakness proves you've got a kind soul."
"...Sis."
"And a woman's role is to protect men with kind hearts like yours. Just like how I always come running when I hear you crying."
Yes, just as she said—she'd always protected him. When he was bullied, she'd confront them first; when he was in danger, she'd rush to save him. She was like a fairy-tale hero, a knight guarding her prince.
"So don't blame yourself for being weak. No need to hold back your tears. You were born that way, and I was born to protect a Seiji like you."
"...Really?"
"Of course~ Have you ever known me to lie?"
He loved that sister. In a world full of fears, she gave him the courage to live boldly.

"So don't worry too much. As long as Seiji's by my side, I'll always protect you!"
That's why Seiji had always found solace in his sister, always consulting her in tough times. Forgetting at some point that it stemmed from her love for him. Taking her kindness for granted, as natural as breathing.
"Haa, haa... ♥"
But even that wouldn't last forever. As if to prove it, an unfamiliar moan escaped his sister's lips right now. Her naked body slick with sweat, taking in the cock of the man he could call his enemy.

"Ngh, haa... Haa, haa... ♥"
Why? Why was the sister who'd always protected him now frolicking in that man's arms? What had that bastard done to make her wear such an ecstatic expression?
"Doesn't it hurt?"
"I-It's fine. It was overwhelming at first 'cause it's so big, but now I'm used to it..."
Her voice dripped with affection for him. Like the whispers of love she'd once given Seiji... No, maybe even stickier, deeper emotion.
"Hehe, I didn't know yesterday, but a man's cock feels like this."
"Probably different from other guys. Mine's just huge."
"Pfft, yeah, compared to my little brother, it's a world of difference."
Grind. The moment she mentioned him, Seiji ground his teeth, his hands trembling. For her to put him on the same level as that guy—it was more humiliating than anything.
You said you loved me. Said you'd protect me. So why use me as gossip fodder and laugh with him? What makes that bastard so special that the sister I knew is ruined like this?
"Can I kiss you?"
His tender whisper choked Seiji's breath. His wide eyes caught his sister blushing shyly, pulling his body close.
-Smack, muah.
A kiss in place of words. A sticky, sloppy act laced with true affection he'd never even shared with his own sister.
-Squelch, squelch!
Even as it happened, his hips pistoned roughly, shaking her body into wild waves. Aroused further, he asked carefully.
"Feels good?"
She answered.
"Y-Yeah~ ♥"
With utter ecstasy, laced with anticipation.
"Can I go faster?"
"Uh, y-yeah. Harder..."
-Squelch, squelch!
"Haa, ngh, haa... ♥"
The act intensified the moment she consented. Seiji, watching, froze in place, speechless. He wanted to burst in and stop them. Demand an explanation from his sister. But his hand drifted away from the doorknob.
And that hand eventually reached his lower body, where his pants were half-off, exposing his pathetic dick.
'Wh-what? Why...'
It was hard. Physiologically aroused by the humiliating, disgusting sight of his sister being fucked.
"Aidrian's body looks so sturdy up close."
The more she expressed fondness for him, the louder the ringing in his ears. The more that bastard responded, the whiter his mind went.
"Been training hard."
"Hehe, feels weird. I'm always the protector, so leaning on someone like this is kinda novel."
Emotions she'd never shown him. Comparisons to him. Even the privilege only he had enjoyed was being stolen in this moment...
"Still, even if it's just words, it makes me happy. Feels like some empty part inside me is getting filled."
The expression she never wore around him appeared then, and his conscious control slipped to instinct, urging his hand to move.
"Hey, Senya, can I ask one favor?"
"Hm? What...?"
No, don't.
"Call me Master."
Don't play along anymore. Don't humiliate me further.
"M-Master? You know I'm Lord Renes's knight, right?"
"Just for the vibe. Can't you?"
But his desperate pleas were just empty echoes. Responding to the faint hope blooming within, a shy whisper slipped from her lips.
"M-Master...?"
-Crack.
His vision split. As if the world crumbled, his soul shattering.
"More specifically."
"Like how?"
"Like this..."
His lips brushed her ear. In a closeness Seiji could never enter, whispering words he could never demand.
"M-Master..."
And she accepted it, opening her mouth. Uttering words no proud knight should, crumbling her pride to lust, shyly voicing them.
"Please... make this clueless virgin slut... a total mess tonight..."
"Hngh, mmph..."
His breath caught. Terrified his own moan from this sight might be heard, he clamped his free hand over his mouth. Not wanting to be caught. Unable to stop.
"Urgh! Senyaaa!!!"
Aroused to the peak, he sprang up. Lifting her body in that position, he rammed his monstrous cock into her savagely.
"W-Wait, this position's too embarrassing... Ahhk!"
-Plap! Plap!
"A-O-O-O-O, Oooh~ ♥"
From above, like pounding a stake. Her breath choked under the intense blows. Yet he didn't stop, pushing her relentlessly. Ignoring her strong face twisting grotesquely, he drove her on.
"Haa, haa. Senya!! I'm at my limit—can I cum inside!?"
"A-Uh, Ooooh... Ungh... ♥"
"Inside you—gonna fill you up!"
His roar sped his thrusts. Her wrecked face lifted fiercely as his hips bucked high. And then spuuurt, splurt. Sticky fluid erupted.

"O-Ugh, ok... ♥"
Taking that massive load, she moaned as he finally lowered her to the bed with a satisfied grin.
"Hoo, standing carry's tough..."
"Haa... ♥"
Senya trembled on the bed, lost in afterglow. Staring endlessly, Seiji realized his stopped hand was sticky. Compared to that monster's output, his meager white dribble was pathetically small...
"So, now that you've done it sober, what's your take on sex?"
As he stared blankly, her dazed eyes refocused, answering in a trembling voice.
"D-Don't know. Ended too fast... But it's addictive somehow... ♥"
"Round two?"
"Y-Yeah... Please... ♥"
Starting again? But Seiji had no will to watch more. Normal men calm after one release. Unlike him, eager for more with his sister—Seiji felt only self-loathing for getting off on her disgrace.
"Feels kinda guilty though. Your brother might flip if he knew."
"Hehe, don't worry about him. I'll handle it... Just play along later."
"That easy?"
"Well, he's a grown-up. Time he stood on his own."
Focused on their act, ignoring him completely. Unable to watch more, Seiji turned away, shuffling off in tattered steps. Sadly aware the cracks in his heart had collapsed into rubble...
The next day, after fooling around with Senya, she watched my training and bitterly shared her recent news.
"Heard Seiji quit the knights today."
"Your brother?"
"Yeah, left me just a letter saying he's heading back home... Guess what happened with you hurt him bad."
"...Kinda feel bad now."
"Nah, don't sweat it. Probably had some epiphany or whatever."
An epiphany, huh. Senya tried seeing her brother's choice positively, but knowing the reason, I felt a bit uneasy. They seemed close—maybe showing off that piledriver in front of his crutch sis was too much? Nah, thinking back, that punk called me a whore-monger to my face. Good sis, shitty brother—why'd he turn out so rude?
"Yoo-hoo~ Hey! We're here~"
A cheerful voice cut through the bitterness as I trained. Looking over, sure enough, Martina and Helia approached.
"Oh, you two. Mission go smooth?"
"'Course~ Nothing's too tough for me. Easy as pie~"
Martina puffed out her hefty tits proudly. Spotting tense Senya beside me, she zeroed in.
"That face looks familiar."
"I-I'm Senya of the knights. Honored to meet Three Knights Martina and Helia."
Senya bowed politely. Right, she's technically their subordinate. As I thought that, Martina eyed me and Senya back and forth, frowning.
And spat out curtly:
"You too?"
"Pardon?"
Senya blinked blankly at Martina, then me. Realizing something, her eyes widened at Martina.
"...You two as well?"
Oh shit, this awkward? As unease hit, Helia sighed, glaring at me.
"Aidrian, I told you not to spread yourself too thin..."
"H-Haha... It just kinda happened."
Yeah, in this world, one guy with multiple women ain't viewed great. But luckily, Helia wasn't as mad as I'd feared. Clearing her throat, she beckoned me.
"We'll talk later... For now, prepare to move."
"Huh? Going somewhere?"
"Lady Renes summons you. Must be for today's match."
Right, time's come. My third bout as the arena gladiator.