My Sister's Romance, My Speedrun

The main romance fantasy storyline was set to begin in one year. For now, the young darling of the Valentine family, Lucian, was pretending to be asleep.

“Are you sleeping well, my sweet Lucian?”

A gentle voice. It belonged to none other than Elysia, the eldest daughter of the Valentine family—the very house that housed the romance fantasy’s female lead.

“You worked so hard today, didn’t you?”

She held the doorknob with her slender hand, gazing at the bed with the warmth reserved for the world’s most precious treasure.

“Sweet dreams, alright?”

With those words, the door clicked shut. -Click.

Lucian remained perfectly still on the bed, not moving a muscle even after the light sound and the fading footsteps. His breathing was steady, rhythmic—flawless simulated slumber.

But inside—

‘Has she left?’

Lucian—or more accurately, the speedrunner broadcaster Kim Jae-hoon who had reincarnated into Lucian’s body—thought to himself.

‘Ugh, I almost missed the launch window.’

The Male Lead’s family was currently visiting the estate as guests. That meant all the aggro in the mansion was focused on the romance plot. ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠Right now, the female lead—his little older sister Rosalyn—was about to step ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠out onto the terrace for some night air and have a fated first meeting with one of the male leads.

And that moment was—

‘The absolute best timing.’

Lucian quietly cracked one eye open. He kicked off the childish, cutesy blanket without making a single sound. A casual swipe through the air summoned a translucent blue window visible only to him.

The comments flooded in the instant he posted.

Lucian skimmed through the replies. Half the gallery said it was doable, half said it wasn’t. But Lucian was one hundred percent certain it would work.

‘Yeah, if I get hit I just die~’

With a 12-year-old shota body that had a hitbox the size of a rat’s tail and 52 agility, slipping between the imperial knights’ blades while doing twists was entirely possible.

With a serious expression, Lucian typed out a follow-up post.

The gallery immediately caught fire at the prospect of a proper speedrun after so long.

Lucian closed the window and turned his gaze toward the window.

“Is there some law that says men have to become knights and women have to wear dresses?”

A clear, ringing voice echoed from the terrace. It was his little older sister, Rosalyn.

“I will protect this family with my own sword!”

“I’m going to become the Knight Commander and crush the pride of every knight in the world!”

Classic tomboy female lead lines, full of fiery determination.

“…Ah.”

The Male Lead was staring at Rosalyn as if spellbound, letting out a dumb groan. Her short hair shimmered softly under the moonlight, and her silhouette stood tall with shoulders squared proudly.

“Lady Rosalyn… you truly are… a most unique and wonderful person.”

The Male Lead’s face flushed red as he stammered, completely captivated by her charm.

The romance fantasy was beginning to unfold between the two of them, but to a dried-up speedrunner like Lucian, it was nothing more than background music.

‘Look at those escort knights staring at the terrace. Aggro is perfectly pulled.’

Romance was romance, and speedrunning was speedrunning.

Right now, with the entire mansion caught up in the romance fantasy atmosphere—right at the moment the absolute laws of the RoFan world kicked in—was the bugged timing when the map’s guard detection became the loosest.

“Keep filming that romance hard, sis.”

Without a single moment of hesitation, Lucian threw himself into the darkness.

“Your little brother’s gonna go do a quick speedrun.”

With those few words, a small shadow shot toward the imperial palace at terrifying speed.

‘Huff… huff!’

His heart felt like it was about to explode. A body with only 2 stamina was forcing out the speed of 52 agility; there was no way it could handle it.

‘If I hadn’t swiped that continuous healing artifact from big sis’s room, I’d already be dead.’

The brooch-shaped artifact glowed softly against his chest.

‘Even with the artifact’s buff, one hour is the absolute limit.’

‘I have to raid the treasury and restock artifacts within that time. Otherwise I’m actually finished.’

Before long, the massive, majestic front gate of the imperial palace loomed ahead. Imperial knights stood firm before the tightly shut doors—a wall that could not be breached by normal means.

But there was a confirmed opening timing.

According to the original story, the trashy Second Prince would pass through the main gate at this hour on his way to some sleazy place.

A small blue window compressed on his wrist displayed a running timer.

‘It took 20 minutes just to get here. The prince’s carriage should be visible any second now…’

Lucian slowed down and grabbed the hem of his childish pajamas with both hands.

-Riiip!

In an instant, he tore the expensive silk garment to shreds. All that remained was a pair of panties and rags.

‘It’s coming! The carriage!’

Lucian smeared dirt from the ground all over his face, then launched himself into the air at the exact moment the Second Prince’s carriage appeared through the opening gates.

“Please, just one coin…”

The sudden appearance of a filthy child right in the middle of the gateway sent the knights and coachman into a panic.

“W-what the—?!”

“It’s a kid?!”

Confusion was immediately followed by an order.

“Just run him over.”

The Second Prince’s voice was far more rotten than expected.

“Filthy little beggar brat. Don’t stop the carriage—just crush him!”

A command truly worthy of a trash prince. The cruel order froze the air in front of the gate for a moment.

A brief moment of shock. A shift in attention.

‘Yes. That’s exactly it.’

That was precisely what Lucian had been aiming for. The knights’ heads turned for the briefest instant at the prince’s shocking statement and the carriage that showed no sign of slowing down.

The narrow gap between the carriage floor and the ground. In that short moment, a perfect blind spot opened where everyone’s gaze had completely vacated.

‘Okay. Second Prince gate-skip complete!’

Lucian’s eyes flashed. Using the hand he’d stretched out in a begging gesture to push off the ground, he dove straight under the carriage.

-Swoosh.

His small body slipped beneath the carriage like smoke. There was no time to look back. Lucian immediately broke into a full sprint.

“Huh…? What?”

The coachman found it strange that no pained scream had rung out even though they should have run the child over.

“The kid didn’t get stepped on…”

The knights who had been standing there stupidly suddenly shouted—

“He ran inside!”

“Intruder! There’s an intruder in the imperial palace!”

“An intruder?!”

“The target is a small-statured male!”

In an instant, magical alarms blared across the entire palace and emergency protocols were triggered. Elite knights poured out from every direction.

The first knight to reach him swung his blade down from above, but Lucian calmly read the knight’s shoulder muscles and the direction of his pupils.

‘Pattern A.’

He had practiced this to death in the Speedrun Gallery just for today. Lucian let the blade flow past him. The sword that missed him by a single millimeter was followed immediately by another knight’s swing.

‘This time it’s horizontal slash Pattern B.’

Lucian ducked his head ever so slightly, letting the blade brush past his hair.

‘Frame evade~’

To the knights, the kid in nothing but panties must have looked like he could see the future.

“How the hell is this crazy brat dodging everything?!”

“Surround him! Restrict his movement!”

The knights screamed in shock, but Lucian danced and twisted between their blades like he was performing, charging straight toward the heart of the palace.

‘Turn here and it’s the palace servants’ quarters.’

Without hesitation, Lucian kicked open the massive door and burst into the residential wing. The sound of the imperial knights’ armor clattered loudly as they chased right behind him.

“Stop right there! No matter where you run, it’s a dead end!”

“No backseat gaming, thanks.”

“You little rat, all you’ve got is a big mouth!”

The short, arrogant reply made one knight completely lose his temper and swing his sword. The strike carried terrifying power.

But Lucian had already positioned himself perfectly in front of a locked door just before the attack landed.

“Huh?!”

The knight’s slash shattered the firmly locked doorknob. Lucian quickly opened the door and slipped inside the room.

To a stamina-2 shota without any lockpicking skills, an elite knight’s ridiculous power was the perfect door-opener.

“Kyaaaah!”

As the servants screamed, Lucian checked the knight’s eyes. Pattern C. He took a light step. The knight who followed swung his sword diagonally. The servant’s position lined up perfectly with the knight’s blade path.

“Eek?! K-Knight sir?!”

“Huk!! Stop the sw—!”

No matter how enraged the elite knights were, they couldn’t cut down palace servants without orders from above. The moment the knight twisted his sword and lost balance, Lucian sprang like a coil into the next room.

‘This is the peaceful Friend Shield technique I invented!’

“Uwaaah! Mommy!”

“Don’t swing that thing around here! Move!!”

“You idiots!!”

Every time the knights tried to swing their swords while sprinting down the corridor, Lucian positioned himself so they would inevitably hit the servants. Simply standing in the optimal spot completely blocked their attacks.

‘This is exactly where the knights are vulnerable.’

In a RoFan world obsessed with one grand narrative, the imperial knights were only used to clashing swords with male leads or purging the families of rebellious young ladies. They had zero preparation for this kind of speedrun play.

Lucian twisted the corner of his mouth into a smirk.

‘If I take advantage of the fact that this is a romance fantasy world, I can route even the imperial palace.’

After turning the servants’ quarters corridor into a wasteland, Lucian unleashed his true top speed.

-Shwoooosh—!

He looked like a ghost shooting forward. But because of his stamina stat, he couldn’t maintain that speed for long.

“Where did he go?! Where did he disappear to?!”

“Right corridor?! Or left?!”

The knights had completely lost sight of Lucian. Once he was out of their field of view, he slipped into the laundry room he had destroyed earlier.

-Swish.

Lucian snatched a trainee maid uniform hanging on the drying rack and changed into it.

‘This is only possible because I’m still twelve.’

In just ten seconds he completed a perfect cross-dress. He slowed his frantic pace and instantly transformed into a terrified low-ranking maid.

He was male, but still a young Lucian. Moreover, he was the younger brother of the world’s most beautiful RoFan female lead. Thanks to his delicate features, wearing a skirt didn’t look strange at all.

-Swish.

He naturally blended into the line of low-ranking maids fleeing outside.

“Just what is this vulgar commotion?”

At that moment, a girl armed with nobility and elegance appeared at the end of the corridor, escorted by knights. Gorgeous golden hair and the arrogant eyes typical of the imperial family. It was the Princess, who appeared in the original story as Rosalyn’s rival.

The fleeing maids all stopped at once and bowed their heads.

‘It’s the princess?’

She looked younger than in the original, but the impression was similar. As the Princess approached to personally handle the situation, Lucian deliberately tripped and fell.

“Ah…!”

The clumsy sight of a low-ranking maid who had fallen in surprise. Naturally, the Princess and her escort knights’ gazes all locked onto Lucian.

Among them, a sharp-eyed veteran knight saw through the disguise.

“This bastard is the intruder! Stand back!”

He drew his sword, having seen through Lucian’s disguise—but he hadn’t realized the gender was also faked.

With his life on the line, Lucian simply enjoyed the moment and perfectly acted out the role of a tragic heroine.

“Knights, attack all at—!”

“Stop.”

Just as the knights were about to radiate killing intent, the Princess gracefully raised her hand and stopped them.

Lucian cheered inwardly.

‘No matter how much of an intruder it is, they won’t immediately kill a pretty, pitiful-looking female character, right?’

The cross-dressing had been a calculated move targeting the weaknesses of the RoFan world.

“I can hardly believe such a small and pitiful child managed to break through the palace barrier and the knight order.”

“What circumstances could possibly drive you to commit such a bizarre act?”

“Speak with your own mouth.”

It was the textbook beginning of a story. Lucian perfectly reproduced the expression of a tragic heroine from a misery porn novel.

“That is… my family…”

The Princess and the escort knights’ gazes were completely focused on his pitiful lips. The atmosphere suggested that one more sentence would trigger a touching flashback.

But to a veteran speedrunner, cutscenes were nothing but targets for forced skips.

“Skip.”

Lucian suddenly uttered a completely random word in the middle of his sentence. His expression turned ice-cold. At the same time, his top speed exploded once again.

-Shwoooosh!

Lucian shot forward in a straight line toward the Princess standing right in front of him.