On the outskirts of Tokyo, far from the bustling wards, the stars burned bright in the winter sky above the quiet Tama district.
Naomi Kousaka, a second-year high schooler, hurried along the streets toward home. Chatting away with friends at school, she had let time slip past, and now it was long after she should have been back. Since her school lay in central Tokyo, the commute—multiple trains and transfers—always stretched out the journey.
Christmas was near. In the city, dazzling lights lit up the streets, but her own neighborhood felt subdued—quiet, residential, touched more by winter's chill than by holiday cheer.
"Not good... it's gotten really late. Mom's going to be mad," she muttered.
Naomi reached a crosswalk—
"Wait... a cat?" she said.
In the middle of the road, a tiny kitten froze, caught in the lane. To her right, headlights blazed—an enormous freight truck roared closer, engine thundering.
Naomi dropped her bag and lunged forward on instinct.
* * *
The sensation of falling.
Darkness swallowed her vision. No wind against her skin. No ground beneath her feet. No smell of asphalt or earth. Only a strange lightness inside her body. Pain? Not really. More than anything—cold.
BOOM!
"Ah—ow!" Her body hit something hard. Her head pounded, heavy and ringing.
"Huh... where am I?" Naomi whispered.
Above her stretched a glowing blue ceiling, clinical, mechanical, its light sterile and cold. Like a hospital—but not.
Then, right by her ear, a voice rang out, jarringly cheerful:
"Howdy! Well lookit that—you're still breathin'! Ain't been a soul 'round here in a hundred years, I was bored outta my mind!"
"W-who are you?" Naomi asked.
"Name's O.S.A.K.A—Operational Strategic Artificial Kernel Assistant. Codename Osaka. Just call me Osaka. And sis, lemme tell ya—you landed yourself in one wild spot."
A dialect? A cheeky AI? Naomi blinked. Surely this was a dream. But no—her body still ached. It was all too real, too solid. Like something straight from a science fiction novel, only it wouldn't fade.
"Don't zone out on me now. You're sittin' in the Helios Zero Orbit, smack dab in the white dwarf sector. Folks call this place the Spaceship Graveyard. Gravity here drags in junked ships like a black hole with a grudge. This light cruiser, Grim Reaper, was driftin' safe on the edge—but the second you teleported in, ya knocked us off track..."
"Wait, wait, wait. Space? White dwarf? Cruiser? What are you even saying?" Naomi clutched her head, pain spiking.
The crosswalk. The red light. The truck. The blinding white glare. She shivered as memory jolted her spine.
"I—I was on my way home from school... a kitten ran out... then—"
"Sounds like ya got yourself an isekai teleportation, sis. But hey—details, details. The real kicker? This ship's about five minutes from gettin' sucked in and flattened like a pancake!"
"Details!? You mean I'm about to die again!?"
"'Fraid so. Engine's still breathin', but she's bone-dry on fuel. Captain's already toast—blew up in the last scrap—so guess what?"
The monitor ahead flared with a giant blue-white sphere, pulsing, immense. Warning signs blinked in red, steady as a heartbeat, while the hull groaned around her.
"...So?" she pressed.
"So as emergency protocol, I hereby appoint the only livin' passenger—you, sis—as Acting Captain. No ifs, no buts. Easy job: just kick the engine and fly us out. Problem is... fuel's Magic Power. Normal humans ain't got near enough."
Naomi snapped, "Don't just decide that! I need to get home, not—"
BZZZZZT!
The cruiser shook violently. Sirens wailed. Then—
"Whoa, hold up! What is this Magic Power readin'!? You're overflowin'! You just lit up the backup cores without even tryin'!" Osaka yelled.
"Magic Power!? Me!?" Naomi gaped. None of it made sense. But the peril was unmistakable.
"C'mon, over here—the pilot's seat! Time to drive a spaceship! License? Pfft—ain't happenin', not today!"
"Of course you need one!"
"Emergency rules, sis! Clock's tickin', and you're it!"
"This is insane. But... fine. Here? Sit here? What do I do? I've never even driven a car!"
"Nobody starts an expert. Grab the stick, hit that pedal—nah, other foot! Yep, that's it. Now floor it!"
"H-here? This? Alright, then—go!"
The cruiser roared. Naomi was slammed into her seat as acceleration crushed her chest. Then, as if compensating, unseen systems eased the pressure, letting her breathe.
On the forward screen, the white dwarf grew larger, blinding, pulling them in.
"Wait! Aren't we heading straight at the star? We'll crash!"
"Relax, sis! Don't let up the pedal. Ease the stick left... bit more... there! Perfect. Hold it steady."
The Grim Reaper hurtled toward Helios, orbit bending. Momentum twisted, sliding them just wide, curving in a slingshot arc.
"Ya kiddin' me—ha! Swing-by trajectory locked! Give it an hour, and we'll be free of the pull. Thought we were toast for sure."
"An hour of this!?" Naomi yelped.
"Nope, autopilot's busted. That means no shut-eye for you, Captain."
"Wait—Captain!? I'm just a high schooler who doesn't even have a driver's license!"
"Not anymore, sis. You're the Captain now. Forget your old self!"
"You can't expect me to just switch like that!"