Kai didn't know he is reincarnated as canon fodder

In a dimly lit, cramped room, filled with the soft hum of multiple computer fans, Astor was slumped over his desk. Mountains of manga, figurines of his waifu collection, and half-eaten bags of chips surrounded him. His life, if you could call it that, was a continuous cycle of anime, video games, and junk food.

But even in this state of aimlessness, Astor often daydreamed of a different life. "Damn, if only I could get a do-over," he'd think to himself after a particularly bad game round or upon seeing the protagonist in one of his favorite isekai series living their best life.

One fateful night, after binging on a new series till 3 AM and surrounded by empty energy drink cans, Astor's wish was unexpectedly granted. With blurry vision, he clicked on a suspicious-looking pop-up ad that said, "Wanna start over? Click here for a new life." It sounded like the start of a visual novel he once played, but before he could even process it, his world went black.

Sunlight pierced through unfamiliar curtains. Astor... or was he still Astor? Groaning, he slowly sat up. His room was vastly different—spacious, clean, adorned with what appeared to be... medieval decorations?

Feeling strangely more athletic and less sluggish, he found his way to a mirror. Staring back at him was a younger, more handsome face with sharp features, although the eyes—those were still unmistakably Astor's.

"Dude... did I just get isekai'd?" He whispered, wide-eyed.

Suddenly, the door burst open, and a tall, formidable-looking man stepped in. "Ah, young master Kai, you're finally awake. Your training begins today!"

"Kai? Training? Bro, I just wanted to level up in my MMO, not in real life," Astor thought.

The man, apparently his butler, handed him a peculiar-looking device. "This, Master Kai, is your life slate. It will assist you in your daily tasks."

Examining it closely, Kai (formerly Astor) realized it functioned similarly to a tablet. His gamer senses tingling, he smirked, "I got this."

Kai, all of 13 years old, with a mop of unruly hair and the unmistakable awkwardness of early adolescence, blinked against the sunlight filtering into the room. His surroundings felt eerily familiar, like a mash-up of a medieval fantasy game and a typical teenager's room.

The door creaked open to reveal a tall man in a well-tailored suit. "Ah, young master Kai, you're awake," he said, handing over a sleek device.

Kai squinted at the device. "Is this some sort of tablet? Kinda looks like the one I had..." His voice trailed off. Memories of late-night gaming, anime binges, and the endless cycle of his NEET life as Astor began to resurface.

The so-called 'life slate' seemed oddly intuitive to Kai. After a few swipes, he got the hang of it, his fingers moving with the confidence of someone who had spent countless hours on similar devices.

His youthful curiosity piqued, but skepticism bubbled within. "Yo, is this some sort of VR game? It's mad realistic!" He glanced around, half-expecting to see a logout button or some telltale sign of artificiality.

The butler, with an air of stern authority and a hint of reprimanding warmth, raised an eyebrow. "Master Kai," he intoned, "such language isn't suitable, especially in front of Lady Yumiko. And do remember, young Miss Ryoko looks up to you. It'd be unfortunate if she picked up such... modern vocabulary."

Kai, for a moment, was taken aback. The words "mother" and "sister" echoed in his mind. Family. A concept so foreign yet so dearly yearned for in his past life. The sheer possibility of having a family now wrapped around him like a comforting blanket.

His eyes, which always held a touch of mischief and youthful rebellion, softened. The weight of the loneliness he'd felt as Astor hit him full force. Those nights when he'd wished for someone, anyone, to share his joy, his sorrow, or just to simply exist alongside him—those nights felt like a distant memory, yet the sting was fresh.

Kai took a deep breath, trying to keep his emotions in check, but a singular tear betrayed him, rolling down his cheek. "I... I have a family?" His voice wavered, revealing the raw vulnerability of a child craving love and connection.

The butler, seeing this display of emotion, seemed momentarily taken aback. Then, with a gentler tone, he replied, "Indeed, young master, it's cold to pretend they aren't your family. And they are most eager to see you."

For the first time in what felt like forever, Kai felt a surge of warmth, of belonging. The walls he'd built as Astor began to crumble, making way for hope and a new beginning. He wiped away the tear, determination replacing his earlier skepticism.

"I'll try to be better," Kai murmured, holding the 'life slate' close. "

He decided to ask about life slate after ward...since he wishes to meet his new family...

<40 minutes before>

Ryoko, a petite 12-year-old with a cascade of raven-black hair and the hesitant uncertainty of early adolescence, blinked at the bright sunlight streaming into her room. The decor felt strangely out of time, a blend of medieval tapestries and trinkets that could belong in any teen girl's room.

Ryoko, still processing her surroundings, was momentarily startled by the soft touch of a maid on her arm. The maid, with a warm smile, had delicate features and a calming presence.

Ryoko padded softly across the marble floor, her pastel dress swaying with each step. As she approached the imposing double doors of her mother's chamber, she hesitated.

Her fingers reached for the door handles, then paused. She let out a quiet breath, eyes darting around as if searching for courage. Giving a light, almost tentative knock, she waited.

The door slowly opened, revealing the room's sunlit warmth. Ryoko bit her lip, stepping in with a mix of excitement and shyness. Her presence was like a soft whisper, easy to miss but impossible to ignore.

Ryoko entered the chamber, and her mother, Lady Yumiko, turned her gaze towards her. Elegance radiated from every inch of her being, but her eyes held an undeniable fatigue.

"Ryoko," she said with a soft sigh, "please head to the dining hall. Your brother will join you shortly."

With a nod, Ryoko turned to leave the chamber. As she moved through the corridors, the hushed conversations of the servants became audible, though they thought themselves discreet.

"Did you hear?" one whispered, "Master Kai once struck Lady Yumiko. Such audacity!"

Another servant, eyes wide with both fear and fascination, replied, "And they say he might've had a hand in Lord Toshiro's death. They never found the real cause."

A third chimed in, her tone dripping with disapproval, "Yet Lady Yumiko continues to pamper him. Why? He's a viper waiting to strike."

They then cast a sympathetic glance at Ryoko, who was just out of direct earshot. "Poor Miss Ryoko," murmured one, "living under the same roof as him. It's not safe."

"Shh," hissed another, looking nervously around, "not now! She might hear you. But you're right. She should be careful."