August arrived, and after the rainy season came the hottest part of summer in Japan.
"Chirp~ Chirp chirp chirp~ Chiiirp~~ Chiiirp~~"
Kamiyā Yuu's upscale apartment was next to a park. From early morning onward, the shrill cries of cicadas never ceased. Even with the windows shut, the piercing buzzing easily penetrated the glass, making it impossible to ignore.
Wearing headphones, Kamiyā Yuu leaned against the wall and sat casually on the apartment floor. The balcony door was cracked open just a little, allowing a gentle breeze to drift inside and stir the curtains beside him.
The apartment was far from the bustling commercial district, making it exceptionally quiet aside from the incessant cicada song. He picked up the manga in his hands several times, only to put it back down again.
"So now I finally understand why people say, 'The cicadas are driving people crazy.' It really fits in every sense."
The constant chirping had left him unable to settle his mind, yet Kamiyā Sora was sleeping peacefully with her head resting on his lap.
She wore a light white summer dress with a simple Gothic design. Beneath the hem, her slender legs were wrapped in translucent white stockings, slightly curled because of the way she lay against him. Her delicate figure and flawless, hazy beauty made her irresistibly charming. One small hand lightly clutched the fabric of his T-shirt, and with her eyes closed, her quiet, adorable sleeping face made Kamiyā Yuu afraid that even the slightest movement might wake her.
"Sora."
"You're just like a clingy little kitten."
Watching her peaceful sleeping face, he smiled and gently stroked her silver-white hair with his right hand. It felt silky and incredibly soft beneath his fingers.
In terms of personality and appearance, she was almost identical to Sora from the 'Yosuganosora' visual novel from his previous world. One could say she was the same Sora from another dimension.
Over the three years since his transmigration, however, her personality had changed considerably. Or rather, nothing about her fundamental nature had changed—it was simply that traits she had once kept hidden gradually surfaced as their relationship deepened.
Her adorable side.
Her willful side.
Her genuine side.
To Kamiyā Yuu, every one of them was perfect.
Perhaps this was exactly the ideal that countless men dreamed of.
Those without a little sister wished Sora weren't one. Those with a little sister wished their sister were Sora.
"Mmm~~"
"Hm?"
As though sensing his gaze, Kamiyā Sora slowly opened her eyes. Sitting up, she looked around in a daze before her eyes settled on Kamiyā Yuu.
Covering her mouth with one hand, she let out a sleepy yawn.
"Good morning, Yuu."
The thin shoulder strap of her summer dress slipped down her smooth shoulder. The languid, slightly disheveled sight almost caused Kamiyā Yuu to lose his composure.
He flicked her forehead with a finger and laughed.
"It's already noon."
"Mhm."
Tilting her head, Kamiyā Sora glanced at the wall clock before remembering that after lunch she'd gotten bored, laid down on top of him, and somehow fallen asleep.
Stretching contentedly, she paid no attention whatsoever to the graceful curves of her body being fully displayed before him. She crawled across the floor into his arms before curiously looking at the manga in his hands.
"What are you reading?"
"A shōnen manga."
Kamiyā Yuu closed the volume so she could see the cover, which bore the unmistakable style of the classic *Weekly Shōnen Jump*.
This world differed from his previous one only in subtle ways. Many things were similar yet slightly different, while others were the same.
For example, Shueisha also existed here, though it wasn't nearly as influential as in his previous world. It was merely considered a first-rate publisher, roughly on par with Chiyo Bookstore.
Taking the manga from his hands, Kamiyā Sora flipped through it before matter-of-factly saying,
"I know. This isn't the newest issue."
"Mhm. It's the one you were reading a few weeks ago."
Kamiyā Yuu rarely reads manga himself. He had only dug it out to pass the time.
Kamiyā Sora suffered from a severe dependence on the internet, and her hobbies were rather limited. She either quietly stayed by Kamiyā Yuu's side or browsed the web.
Whenever they had a day off, she'd always drag him online with her. He didn't actually have to do anything—his role was simply that of a "cushion."
As a result, Kamiyā Yuu knew all about her online interests.
She read manga, novels, watched movies and anime, and played games. She had no particular favorite genre, but she was exceptionally skilled at FPS games.
Whenever she played online shooters with a controller, Kamiyā Yuu had rarely ever seen her lose.
Kamiyā Sora yawned again.
"Boring."
"Yuu, let's play a game."
"A game?"
His interest was immediately piqued.
Since coming to this world, he hadn't touched video games in a long time, nor did he know how far the gaming industry here had progressed.
He had every intention of entering the gaming industry someday—not with Japanese-style card collection games like 'Warship Girls Collection,' but with legendary RPG franchises on the level of 'The Elder Scrolls,' 'Dark Souls,' or 'The Witcher.'
"An FPS."
Kamiyā Yuu shook his head.
"I don't mind, but I hardly have any experience with FPS games."
Even before his transmigration, he had always preferred RPGs over shooters.
The corners of Kamiyā Sora's lips curled upward into a faint smile.
"That's okay. I can teach you."
The living room already had two PS4 consoles connected to a large television that supported PS4 games. They had been prepared specifically so the two of them could play together online, though Kamiyā Yuu's console had spent most of its existence collecting dust.
With practiced ease, Kamiyā Sora powered on the console and soon selected the FPS she played most often—'Modern Battlefield 3.'
Overall, its gameplay was very similar to the single-player FPS titles from Kamiyā Yuu's previous world.
He knew it was one of Sora's favorite games and apparently one of the best-selling single-player titles in this world as well.
As she selected the game mode, he suggested,
"Let's do the campaign."
"Online."
"I'm still a beginner."
"Computer opponents are boring."
Holding the controller, Kamiyā Sora looked full of anticipation.
Under her patient guidance, the two of them soon entered a match together.
The map was set in a modern city. Twenty-four players fought using terrain and various modern firearms.
The graphics were comparable to FPS games from the same era in Kamiyā Yuu's previous world. From a 3D standpoint, they were impressively polished.
However, back in the year 2030, before his transmigration, VR technology had already begun flourishing. VR games had gradually replaced traditional 3D titles as the mainstream, so he wasn't accustomed to playing FPS games directly with a controller anymore.
"Bang bang bang~~ Boom~~ Bang bang~ Clank clank clank!"
Gunfire.
Explosions.
The metallic crunch of tanks crushing abandoned vehicles.
The roar of helicopters flying low overhead.
All the sounds blended.
Instinctively listening to every effect, Kamiyā Yuu's old professional habits surfaced.
"The gun sounds were probably recorded from real firearms. That heavy recoil should belong to an M82A1. Though the gunshot timing is slightly out of sync with the visuals... probably an issue with the recording equipment."
Not long after the match began, Kamiyā Sora rushed straight into the fiercest fighting with a submachine gun.
Even without aim assist, she calmly eliminated enemies with precise single shots.
Bang!
"DOUBLE KILL!"
Bang!
"TRIPLE KILL!"
Bang!
"QUADRA KILL!"
Bang!
"PENTA KILL!"
Bang!
Her eyes remained completely focused on the screen while her nimble fingers danced across the controller like butterflies.
The decisiveness with which she eliminated enemy after enemy left Kamiyā Yuu staring in amazement.
Meanwhile, his own character had already died several times because of clumsy controls.
He wandered around the map, carefully avoiding every enemy he encountered.
Kamiyā Sora's incredible performance quickly attracted the opposing team's attention.
They reacted immediately, forming a coordinated encirclement and suppressing her with overwhelming firepower.
Thanks to all the attention focused on her, Kamiyā Yuu managed to slip deep behind enemy lines and thoroughly familiarize himself with every corner of the map.
"Yuu, what are you doing?"
At last, Kamiyā Sora's character was overwhelmed as the enemy tightened the encirclement, pinned her down with concentrated fire, and even called in helicopter support to finish her off.
While waiting to respawn, she curiously looked over at Kamiyā Yuu's screen.
She discovered that he was casually wandering around inside the enemy spawn area.
A moment later, a freshly respawned enemy shot him dead with a single bullet.
Kamiyā Yuu set down his controller, casually patted her head, and replied,
"Learning the map."