Mitsuru Kobayashi was currently in a dilemma. It wasn't the standard existential crisis one might expect from realizing they had transmigrated into another world—no, he'd already processed that particular bombshell three days ago. And truth be told, unlike the protagonists in those web novels he used to read, he had no complaints whatsoever.
In his previous life, Mitsuru had been born to a single mother. Life had been decent, comfortable even, until everything came crashing down in the most cliché way possible. His mother and unborn sister died during childbirth, and something fundamental broke inside him that day. The world lost its color, its meaning. He'd drifted through the years that followed like a ghost, unable to form genuine connections, always searching for something—anything—that made him feel truly alive.
He'd found that feeling in the most reckless places imaginable. Jumping off cliffs without a parachute, free-climbing mountain faces that would make experienced climbers pale, fighting in underground clubs where broken bones were considered getting off light, even underground sword fighting where one wrong move meant permanent damage. Those heart-pounding moments when death breathed down his neck were the only times he felt really alive.
So why was he perfectly content with this transmigration business? Simple. While he'd been transported to another world, he occupied the same body as his previous life—same face, same build. More importantly, his sister was alive in this world.
His cute little Akane.
From the moment he'd regained the memories of this life, from the instant he'd seen her small face and heard her voice, Mitsuru knew with absolute certainty that he would lay down his life for her without a second thought. She was the second chance he never thought he'd get.
But that wasn't the dilemma keeping him up at night.
Three days ago, along with his transmigration, he'd received a system. Not just any system—a world-hopping one, perfectly tailored to his thrill-seeking nature. High risk, high reward. It would transport him to different worlds with a temporary perk, and whatever he gained there—skills, abilities, knowledge—would be his to keep. The old Mitsuru, the one who lived for the adrenaline rush, would have tried it within hours of discovery.
But that Mitsuru didn't have a little sister waiting for him at home.
If something happened to him in another world, even if he personally didn't care about dying, Akane would be devastated. That thought alone had been enough to make him swear off the system entirely, to let it gather dust in the back of his mind while he focused on being the brother she deserved.
That resolve had held strong for exactly one day.
The first crack appeared during the student council meeting about the cultural festival.
Mitsuru had been sitting in the designated spot for club representatives, already knowing what was coming. President Saeko had conveniently "forgotten" about the meeting again, leaving him—the vice president—to deal with the student council's demands.
"Kobayashi-san."
That voice, cool and precise, cut through his thoughts. He looked up to find Kaguya Shinomiya staring at him with those crimson eyes, her expression hovering somewhere between exasperation and resignation.
"Shinomiya-san," he replied evenly.
She let out an sigh, the kind only someone of her breeding could make sound dignified rather than rude. "Let me guess—Busujima-san is absent again?"
"She had something important come up," Mitsuru said, keeping his face straight. They both knew it was probably just another excuse to skip boring administrative work. From his memory he knew that before he joined the Kendo club the president was quite diligent about these thing but after finding a convenient worker like him, she had let it all go and only focused on swinging the blade.
"Something important," Kaguya repeated, her tone making it clear she didn't believe that for a second. "This is the third meeting in a row, Kobayashi-san. At this rate, I'm starting to wonder if your club even has a president."
"Oh, we definitely do. She's just... strategically delegating."
"'Strategically delegating' administrative responsibilities to her vice president while she does as she pleases?" Kaguya's eyebrow arched. "How convenient for her."
The moment he'd recognized her—really recognized her as Kaguya Shinomiya from the anime—reality had shifted. This wasn't just some random world. This was an anime world.
"Someone has to handle the paperwork," he said with a slight shrug. "Might as well be me."
"I see." She slid a paper across the table toward him. "Very well. Since you're here—again—I need the kendo club to submit a detailed plan for your cultural festival activities. Budget requirements, space needs, safety protocols, expected participant numbers. The works."
"When do you need it by?"
"End of the week would be preferable. Can you manage that without your president's input?"
"I'll make it work," Mitsuru said, taking the paper.
"I'm sure you will." Kaguya's lips curved slightly. then she turned her attention to the next club representative. "That will be all, Kobayashi-san."
Even after that encounter, he'd managed to maintain his resolve. So what if this was an anime world? He could just ignore whatever drama was brewing and focus on earning money, on giving Akane a comfortable life. The student council drama? Not his problem. Whatever romantic comedy shenanigans were happening? He'd stay far away from it all.
Then came the second roadblock.
Mitsuru pushed open the kendo club room door that afternoon, the familiar smell of wood polish and sweat greeting him. He'd half-expected the room to be empty—most members didn't arrive until later—but the sharp sound of a wooden sword cutting through air told him otherwise.
Saeko Busujima stood in the center of the dojo, her purple hair tied back, moving through a kata with fluid precision. Each movement was perfect, technically flawless, the bokken flowing like water in her hands. She must have heard him entering because she completed the sequence and turned toward him in one smooth motion.
"Kobayashi-kun," she said, a smile playing on her lips. "Perfect timing."
"Busujima-senpai," he replied, setting down his bag. "Shinomiya-san was asking about you."
"Was she?" Saeko's smile didn't waver. "I hope you gave her my apologies."
"I told her you had something important come up."
"And she believed that?"
"Not even a little bit."
Saeko laughed, completely unrepentant. "Well, what's done is done. Those meetings are terribly dull anyway—all paperwork and no actual practice." She twirled her bokken casually. "Speaking of practice, how about a spar? I've been working on something new."
Mitsuru felt his pulse quicken from anticipation. "You just want an excuse to test out whatever technique you've been working on."
"Guilty," she admitted cheerfully. "But you enjoy it too."
She wasn't wrong. The moment she'd said "spar," that old familiar thrill had sparked to life. And that's when he'd recognized her. Really recognized her.
Saeko Busujima. From Highschool of the Dead.
Zombies. Apocalypse. The end of the fucking world.
His blood ran cold even as she continued smiling at him, completely oblivious to his internal crisis. His first instinct screamed to grab Akane and run to the most remote location he could find, to stockpile supplies and prepare for the inevitable undead outbreak.
But reason wrestled emotion back under control. If Kaguya Shinomiya existed in this world, with all her wealth and the Shinomiya Group's influence, surely the world couldn't just end in a zombie apocalypse. They'd have contingencies, resources, something. Right? It was supposed to be rom-com world for fucks sake.
"Kobayashi-kun?" Saeko tilted her head. "Are you alright? You look pale."
He forced himself to focus. "Just thinking about the paperwork Shinomiya-san dumped on me."
"Ah." She waved a hand dismissively. "Don't worry about that now. Let's spar first—you can handle boring forms later."
"You're a terrible influence, you know that?"
"I prefer to think of myself as helping you maintain proper priorities." She tossed him a bokken, which he caught easily. "Ready?"
Despite the zombie apocalypse alarm bells ringing in his head, Mitsuru found himself grinning as he took his stance. This was familiar ground. This was something he understood.
"Always."
The spar was intense—Saeko never held back, and neither did he. Her technique was polished and precise, refined through years of traditional training. His was rougher, practical, born from real fights where losing meant broken bones or worse. The clash of styles made every exchange unpredictable and exhilarating.
"There!" Saeko's eyes gleamed as she pressed an attack. "That's the look I was talking about. You're actually enjoying this."
"Says the person who's grinning like a maniac," he shot back, deflecting her strike and countering.
"Can you blame me?" She laughed, genuinely delighted. "Finally, someone who doesn't treat me like I'm fragile! Do you know how refreshing that is?"
They'd continued until both were breathing hard, grins plastered on their faces. Despite his worries about potential zombie apocalypses, Mitsuru had to admit—this was fun. This was that thrill he'd always chased, but with someone who understood it, who craved it the same way he did.
Maybe, he'd thought then, even if the worst happened, he could handle it. He'd train hard, get stronger, protect Akane, and they'd survive together.
The main roadblock came not from school, but from home.
It was a normal evening. Mitsuru had been in his room, ostensibly doing homework but actually researching everything he could remember about the various anime that might be mashed together in this world. Akane was at a friend's house for a study group. Aunt Kobayashi should have been at work for another hour.
So when he heard the apartment door open earlier than expected, followed by his aunt's tired voice, he'd gone to investigate.
"I'm home," Aunt Kobayashi called out, kicking off her shoes with the practiced motion of someone exhausted from corporate life. She looked up when she saw him, pushing her glasses up her nose. "Oh, Mitsuru. You're here. Good."
"Welcome back," he said. "You're early."
"Got off work early for once—miracle of miracles." She shuffled toward the kitchen. "Where's Akane?"
"Study group. She'll be back around seven."
"Mm. Good, good." She opened the refrigerator, stared at its contents with the hollow eyes of someone too tired to make decisions, then closed it again. "I'll order takeout. Thinking of curry. You good with that?"
"Sounds fine."
It was such a normal, domestic scene. His aunt, tired from work, making dinner plans. Nothing unusual.
Except his aunt was Kobayashi. As in Miss Kobayashi's Dragon Maid.
In his previous life, she hadn't existed. In this world, she'd taken custody of him and Akane after their mother died, giving them a stable home. She was a good guardian—tired and overworked, sure, but she cared in her own low-energy way.
She was also, apparently, destined to encounter a dragon.
"Hey, Mitsuru?" Aunt Kobayashi's voice interrupted his thoughts.
"Yeah?"
"If I... hypothetically speaking... told you something really weird was going to happen, would you freak out?"
His stomach dropped. "Define 'weird.'"
"Like..." She pushed her glasses up again, a nervous habit. "Like, really weird. Supernatural weird."
"Has something already happened?" He kept his voice carefully neutral, but his mind was racing. Had she met Tohru already? Was a dragon about to show up at their apartment?
"Not yet. Maybe. I don't know." She sighed, running a hand through her messy hair. "I'm probably just tired and imagining things. Forget I said anything."
"Aunt Kobayashi—"
"It's fine, really." She waved him off, already pulling out her phone to order food. "Just... if anything weird does happen, try not to panic, okay? I'll handle it."
She'd said it so casually, like she might be bringing home a stray cat rather than potentially a dragon capable of destroying cities. And that was the moment Mitsuru's resolve finally, completely shattered.
Dragons. Potential zombies. Rom-com drama. Whatever else this insane crossover world might throw at them.
How could he possibly protect Akane from all of this with just his current abilities? How could he justify not using the system when the world itself seemed determined to become increasingly chaotic?
He couldn't. Plain and simple.
That night, he'd made his decision.
Now taking a deep breath, Mitsuru spoke in his mind: "Open panel."
The interface materialized before his eyes:
---
Name: Mitsuru Kobayashi
Rank: Unranked
Body: 7 (+) [Peak human 10]
Soul: 15 (+) [Normal human 10]
Energy: 0 (+)
Basic Skills:
- Japanese (Competent)
- Swordsmanship (Novice)
[Tiers: Novice, Beginner, Competent, Proficient, Expert, God, Otherworldly]
Abilities: None
Number of Transmigrations: 1
Initial Template Assignable Points: 10
---
It was elegantly simple—no complicated stat spreads or confusing mechanics. Just three core attributes.
Body encompassed everything physical: raw power, agility, endurance, reflexes. Peak human was rated at 10, and he was sitting at a respectable 7. Not bad for someone who used to jump off cliffs for fun.
Soul measured mental fortitude, willpower, and spiritual resilience. Normal humans averaged 10, but his transmigration had boosted him to 15—apparently having your consciousness shoved into a parallel universe did wonders for mental strength. Who knew?
Energy would be his supernatural power stat once he actually gained any. The system didn't bother with separate measurements for chakra, mana, ki, or whatever else existed. It converted everything into universal energy that could adapt its properties as needed. Currently sitting at a big fat zero, but that would change.
The world-hopping function was the real kicker. The system would select worlds appropriate to his current power level—so no throwing him into Worm or other apocalyptic world. Time wouldn't flow in his home world while he was away, so he wouldn't return to find Akane all grown up or married off to some random guy. That last part was crucial. Anyone who wanted to date his sister would have to go through him first, and he'd make damn sure they were worthy.
Before entering each world, he'd get to choose a temporary talent or perk to help him survive. Nothing permanent, but enough to give him a fighting chance.
His backpack sat ready by his bed—packed with essentials, some non-perishable food, basic first aid supplies. He'd even included the katana he'd been practicing with, a decent blade that felt right in his hands.
The old thrill was back, that electric anticipation that used to fill him before a dangerous climb or a fight. But this time it was different—better. Because this time, he had something worth coming back to. Someone worth getting stronger for.
He was ready.
"Brother?"
Mitsuru nearly jumped out of his skin.
A small head peeked through his slightly opened door. Smooth black hair framing delicate features, amber-like sky-blue eyes that could convince him to do just about anything—his adorable little sister, Akane.
Though he'd never admit it to her face (or anyone else's), Mitsuru was absolutely, undeniably, hopelessly wrapped around her little finger. A doting brother in this life, and probably would have been in his previous one too, given the chance.
"Akane? Shouldn't you be asleep?" He glanced at his clock. "It's past your bedtime."
She stepped fully into the room, closing the door behind her with exaggerated care. "Aunty wanted me to tell you something."
Mitsuru raised an eyebrow. His sister's innocent expression was a little too innocent. "And that something couldn't wait until morning?"
"It's important!" Akane insisted, then paused. "Aunty said you need to do the shopping tomorrow after school. She made a list."
"That's it?" Mitsuru crossed his arms, studying her. "You came all the way to my room, this late, just to tell me about shopping?"
"Well..." Akane fidgeted, her fingers twisting together. "She also said... to bring ice cream. For dinner tomorrow."
"Ice cream for dinner?" His eyebrow climbed higher. "Are you absolutely certain Aunty said that?"
"Y-yes! Definitely! I promise!" She held up her pinky finger. "Pinky promise!"
"Interesting." Mitsuru reached for his phone. "Then you won't mind if I go to Aunty right now to ask what flavor she wants?"
"BROTHER, NO!" Akane lunged forward, grabbing his arm with both hands. "Don't!"
"Why not?" He kept his expression perfectly neutral, though he was fighting back a smile. "If Aunty specifically requested ice cream, I should make sure I get the right kind. Maybe she wants chocolate, or vanilla, or—"
"I—It's not—" Akane's face was turning red. She released his arm and took a step back, crossing her arms defensively. "Fine! Maybe Aunty didn't specifically say ice cream! But she definitely wouldn't mind if you brought some!"
"Uh-huh."
"And—And I'm not asking for myself!" She turned her face away, voice taking on that haughty tone she used when embarrassed. "I just thought it would be nice for the household! A treat for everyone! It's not like I even want ice cream that badly!"
The classic tsundere routine. It was adorable every single time.
"Is that so?" Mitsuru said, his tone carefully neutral. "So if I brought ice cream home tomorrow, you wouldn't want any?"
"I—Well—I mean—" Akane's face grew redder. "If you're already bringing it, it would be rude not to have some! It's about politeness, Brother!"
"Politeness. Right."
"It is!" She stomped her foot lightly. "And anyway, you promised to take me out for ice cream last week but you were too busy with kendo club! So really, you owe me!"
There it was. The real reason she'd snuck to his room.
Mitsuru felt something in his chest warm. This—this was why he'd use the system. Why he'd risk jumping through dangerous worlds. Because this little tsundere who pretended she didn't have a massive sweet tooth, who acted tough but still needed her big brother, deserved to grow up safe and happy.
"You're absolutely right," he said solemnly. "I did promise. That was wrong of me."
Akane blinked, clearly not expecting him to concede so easily. "Oh. Well... yes! It was!"
"Tell you what." He held out his pinky finger. "Tomorrow after shopping, I'll bring home not just any ice cream, but that fancy strawberry-chocolate swirl you like from the convenience store near the station. The expensive one. And I'll make sure we have time this weekend for a proper ice cream outing. Deal?"
Her eyes lit up before she could control her expression. Then she caught herself, trying to look nonchalant even as she hooked her pinky with his. "I suppose that's... acceptable. Since you insist."
"I do insist."
"And I'm only accepting because you promised. Not because I was looking forward to it or anything."
"Of course not."
"Brother, are you making fun of me?" Her eyes narrowed suspiciously.
"Never." He kept his face perfectly straight, then reached out and ruffled her hair. She let out an indignant squeak and swatted at his hand, but he could see her fighting back a smile.
"You're the worst!" She tried to smooth down her hair, but her lips were quirking upward.
"The worst brother who brings you expensive ice cream?"
"...The worst brother who's occasionally tolerable," she amended, then stuck out her tongue at him. "Good night, Brother!"
"Good night, Akane."
After the door clicked shut and he heard her footsteps padding down the hallway back to her room, Mitsuru let out a long breath. He looked at his packed backpack, at his katana resting against the wall, at the system interface still floating in his vision.
Time wouldn't pass here while he was gone. He could jump through a world, gain power, and return in the same instant he left. Akane would never know he was gone. She'd wake up tomorrow, go to school, and when she came home, he'd be there with her ice cream, exactly as promised.
He could do this. Had to do this.
This world was too chaotic, too unpredictable. Dragons, potential zombies, and who knew what else lurking in the background. If he wanted to protect Akane from all of it, he needed to be stronger. Much stronger.
And besides... a small, honest part of him whispered... didn't he miss the thrill? The adrenaline? That electric feeling of truly being alive?
Now he could have both. The thrill of adventure and someone to come home to.
Mitsuru stood, rolling his shoulders and cracking his neck. He picked up his katana, checking the blade one last time before securing it to his belt. The backpack settled comfortably on his shoulders—light enough not to hinder movement, heavy enough to be useful.
"Alright then," he murmured to the empty room. "Let's see what kind of world you've got for me."
He took one last look around his room—at the photo on his desk of him and Akane at the summer festival, at the kendo tournament medals hanging on the wall, at the normal, peaceful life he was about to temporarily leave behind.
Then he smiled—that old reckless smile from his previous life, the one that had preceded every death-defying stunt.
"System," he mentally commanded. "Start the process."
"Ding! Searching for world."