I woke to the sound of a familiar voice, sharp yet warm, cutting through the haze of sleep like a katana through silk.
"Kenji, get up already! Breakfast is ready, and I'm not dragging you downstairs like last time."
My eyes fluttered open, the morning light filtering through the curtains of my Kuoh Town bedroom. Above me, Saeko Busujima loomed, her arms crossed and her Kuoh Academy uniform hugging her curves in a way that made my half-asleep brain stutter. Her long purple hair was tied back, and those piercing eyes—equal parts teasing and commanding—locked onto me. My stepsister, one year my senior at eighteen, was not a woman you ignored.
"Five more minutes," I mumbled, rolling over and burying my face in the pillow. The scent of clean linen was a poor defense against Saeko's presence.
"Five seconds, or I'm dumping water on you," she shot back, her tone playful but with that edge that promised she'd follow through. I groaned, forcing myself upright. My name's Kenji, seventeen years old, second-year student at Kuoh Academy, and—oh yeah—not exactly human. But we'll get to that.
Saeko smirked, satisfied, and turned toward the door. "Katsu curry and rice downstairs. Move it, little brother." The way she said "little brother" always carried a hint of mischief, like she knew it got under my skin. She wasn't wrong.
As she left, I rubbed my eyes, my mind already drifting to the absurdity of my life. See, I wasn't always Kenji, the guy living a cozy yet weirdly intimate life with his stepsister in Kuoh Town. Once upon a time, I was a twenty-three-year-old Italian dude, obsessed with *Warhammer 40k* and *High School DxD* light novels. I'd spend hours painting Space Marines and reading about Issei Hyoudou's misadventures with busty devil girls. Then I died—don't ask how; it's a blank spot in my head—and woke up here, in the world of *DxD*, as a baby with a cosmic secret.
I swung my legs out of bed, glancing at the mirror across the room. A lean, dark-haired teenager stared back, my green eyes flecked with something unnatural—a faint shimmer of void, like stars swallowed by a black hole. I wasn't human, not really. From the moment I was born to my human parents in this world, I was something else: a cosmic entity, a fragment of the primordial void. A status screen had popped up in my crib, like some isekai game interface, listing my name, age, and powers that could make Ophis, the Infinite Dragon, raise an eyebrow. Speaking of Ophis, she showed up when I was a month old, calling herself my "second mother" because my void energy drew her like a moth to a flame. Yeah, my life's weird.
I shuffled downstairs, the aroma of Saeko's katsu curry hitting me like a warm hug. The kitchen was small but homey, our Kuoh Town house a quiet haven despite the supernatural chaos I knew was brewing beneath the surface. Saeko stood by the counter, plating rice with practiced ease, her uniform skirt swaying slightly as she moved. I tried not to stare—tried being the operative word. Look, I'm not a pervert like Issei, but Saeko's presence is… distracting. Always has been.
"Morning, sleepyhead," she said without turning, her voice carrying that teasing lilt. "Thought you'd sleep through the apocalypse."
"If it's Trihexa, I'll just erase it," I muttered, sliding into a chair at the table.
"What are you on about? Little brother"
My void powers—stuff like Void Annihilation Cascade or Metaphysical Void Decree—could wipe out infinite realities, so a world-ending beast like Trihexa was more annoyance than threat. Not that Saeko knew the full extent of my abilities. I kept that part quiet, even from her.
She set a steaming plate of katsu curry in front of me, the golden-brown cutlet perfectly crisp over fluffy rice, the curry's rich scent making my stomach growl.
"Eat up, Kenji. You're not skipping breakfast again."
She sat across from me, her own plate already half-empty. Saeko was disciplined, always up early, always in control. Me? I was the guy who'd rather nap than face the morning.
As I dug in, my mind wandered back to how I got here—not just Kuoh Town, but this life with Saeko. Nine years ago, when I was eight, my dad came home with a new wife and a nine-year-old girl in tow: Saeko Busujima, straight out of *High School of the Dead*. I recognized her instantly, thanks to my past-life memories, but I didn't say anything. What do you even say? "Hey, you're a fictional zombie-slaying badass"? Yeah, no.
Our first meeting was awkward as hell. I was a kid with cosmic powers I barely understood, and she was this fierce, quiet girl who looked like she could slice me in half with a glare. We barely talked for weeks, tiptoeing around each other like strangers. But time has a way of smoothing things out. We started cooking together, cleaning the house, even bathing together—innocent back then, just kids figuring out family. Saeko's mom and my dad were kind but busy, always working late as doctors. When I was eleven and Saeko was twelve, they got an offer to work at a private hospital in the US. They took it, leaving us in Kuoh Town with a hefty allowance and trust that we could handle ourselves. Japan's safe, they said. Kuoh's quiet, they said. If only they knew about the devils, angels, and dragons lurking here.
Saeko and I grew closer, dependent on each other in a way that blurred the line between siblings and… something else. By the time I was fifteen and she was sixteen, things changed. We were alone, no parents, just us in this house. One night, after a long day of sparring (her with a wooden sword, me pretending I wasn't a reality-erasing god), it happened. Our first time. It wasn't planned, just a moment where everything—trust, need, love—clicked. Saeko's always been my anchor, the one who keeps me grounded when my void powers threaten to pull me into some cosmic abyss. Now, at seventeen and eighteen, we're more than stepsiblings. We're partners, lovers, a team. And yeah, it's complicated, but it's ours.
I glanced at Saeko as I ate, her fork moving with precision. She caught me staring and raised an eyebrow.
"What's with the look, Kenji? Thinking deep thoughts again?"
"Just… how good this curry is," I lied, shoving another bite in my mouth. She snorted, not buying it, but didn't press. That's Saeko—sharp enough to read me but kind enough to let me keep my secrets. For now.
I knew more than I let on, thanks to my *DxD* knowledge. Kuoh Academy wasn't just a school; it was a hotspot for devils like Rias Gremory and Sona Sitri. I'd cross paths with them soon, whether I wanted to or not. My void powers—stuff like Abyssal Temporal Null, which could erase entire timelines, or Existential Void Devour, which could consume gods—made me a wildcard in their world. I wasn't here to play hero like Issei, but I'd protect Kuoh Town, protect Saeko, no matter what. If that meant erasing Trihexa or rewriting reality's laws with Metaphysical Void Decree, so be it.
"Eat faster," Saeko said, snapping me out of my thoughts. She was already done, leaning back in her chair, her uniform jacket unbuttoned just enough to make my teenage brain short-circuit.
"You've got ten minutes before we're late. Take a bath after, and don't make me wait too long."
She stood, stretching, then sauntered to the living room, plopping onto the big couch with a lazy grace that screamed she'd wait—but not patiently.
I wolfed down the rest of my breakfast, the spicy curry waking me up better than any coffee. Dishes in the sink (I'd wash them later, promise), I headed to the bathroom. The shower was quick, hot water clearing the last of my grogginess. As I scrubbed, my mind drifted to my powers. Eternal Void Aegis made me immune to pretty much anything—True Longinus, Samael's curse, you name it. Abyssal Omniscience let me sense threats across infinite realities, like a cosmic radar. I'd already caught faint ripples of something big coming—Khaos Brigade, maybe, or Trihexa stirring. My Void Harmony Aura could boost Saeko's strength, maybe even make her sword cut through dimensions if I pushed it. The thought of her wielding void-infused steel was… hot, honestly.
I dried off, changed into my Kuoh Academy uniform—black blazer, white shirt, red tie—and checked the mirror. My void-flecked eyes glinted, a reminder I wasn't just some high schooler. I was the Void Sovereign, a walking multiversal reset button. But to Saeko, I was just Kenji, her slightly lazy little brother who needed nudging to get to school on time.
"Sorry for the wait," I said, stepping into the living room. Saeko was sprawled on the couch, one leg draped over the armrest, scrolling her phone. She looked up, her lips curving into a smirk that made my heart skip.
"Took you long enough," she said, standing and smoothing her skirt. "Come on, let's go. Can't have my little brother flunking out because he's late."
I rolled my eyes but followed her out the door, the morning air crisp and cool. Kuoh Town was quiet, cherry blossoms lining the streets, the kind of picturesque calm that hid its supernatural underbelly. Saeko walked beside me, her school bag slung over one shoulder, her posture relaxed but alert. I knew she carried a bokken in that bag, just in case. *High School of the Dead* instincts die hard.
As we headed toward Kuoh Academy, my mind churned. I knew the players in this world—Rias, Issei, Akeno, Asia. My powers could outclass them all, but I wasn't here to dominate. I just wanted to keep this life, this home with Saeko, safe. My past-life memories of *DxD* gave me an edge, but they also made me paranoid. What if the timeline shifted? What if my void powers drew something worse than Trihexa? Ophis, my so-called second mother, hadn't shown up in years, but her promise to watch over me felt like a double-edged sword.
"Kenji, you're spacing out again," Saeko said, nudging my shoulder. Her touch was light but electric, a reminder of how close we'd become. "What's on your mind? And don't say 'nothing.' I know that look."
I hesitated. Telling her I was a cosmic entity who could erase infinite realities wasn't exactly breakfast-table talk. Neither was admitting I knew we were in a world of devils and dragons. "Just… thinking about school," I said, lamely. "And you. You know, the usual."
She laughed, a soft, genuine sound that made my chest tighten. "Smooth talker. Save it for the girls at school." Her tone was teasing, but there was a possessive edge, like she knew I was hers first. The harem thing? Yeah, it was inevitable—my void powers and *DxD* knowledge practically guaranteed it—but Saeko was my anchor. Always would be.
We reached Kuoh Academy's gates, students milling about, the air buzzing with chatter. I scanned the crowd, my Abyssal Omniscience pinging faintly. Something was off—not Trihexa-level, but enough to make me wary. Maybe a stray devil, maybe one of Rias's pawns sniffing around. I'd deal with it if it came to that.
Saeko glanced at me, her eyes narrowing. "You're doing that thing again. Like you're seeing something I can't."
I forced a grin. "Just checking for perverts. Gotta keep my big sister safe, right?"
She rolled her eyes but smiled, linking her arm with mine as we walked through the gates. "You're hopeless, Kenji. But you're mine."
Her words hit harder than any void power. As we stepped into Kuoh Academy, I knew this was just the start. Devils, dragons, and cosmic threats were coming, but with Saeko by my side and the void at my command, I was ready. Or at least, I hope I was.