The Arrival of the Yandere Sister

My name is Ryujin Wan.

6 a.m. sharp, the alarm clock blinked into my waking consciousness. Mornings were crucial — every second counted. First on the agenda was a cup of potent black coffee to jumpstart my metabolism and awaken the senses.

In the early days of my routine, inspired by a particular caped bald guy from popular culture, I began with a humble 10 km walk — an excellent tour to clear the mind and get the heart pumping. But as my body grew accustomed to the distance, it was clear the initial 10 km had become child's play. So I escalated, doubling, then tripling the length. Now, I'm up to a staggering 1000 km.

Here was the kicker: no magic, mana, or cheats — just pure physical exertion. I was stringent about this for a reason. As magical as mana could be, it was a crutch, and I had no intention of becoming dependent on it. I wanted to emulate Tim, a paragon of human strength and skill, absent of any supernatural aid.

While 1000 km might sound outrageous to some, it wasn't just a mad sprint. It was a mix of various endurance and speed training forms — interval runs, hill sprints, and distance jogs. Each added a unique challenge, keeping both my body and mind engaged. Between these bouts of cardio, I worked in resistance exercises, targeting different muscle groups to ensure overall physical development.

After the grueling morning run, I headed straight to my private gym — my sanctuary for muscle and steel — located just a stone's throw away from my room. Yep, I've got a gym all to myself. Luxury? No, necessity.

"Master, you really need to take a break," Amanda chimed in, interrupting my third set of deadlifts. She often popped by during my workouts, a self-appointed guardian angel hell-bent on ensuring I didn't overexert myself.

"No, Amanda, you don't get it. I have to —"

"Get stronger and catch up with Tim. I know, I know." 

She finished for me with a roll of her eyes. 

Look, I get it. She's concerned, but her concern isn't getting me anywhere.

The truth is, it's not just about me; it's about Tim. My good old, non-magical, power-packed Tim. If he somehow made his way into this world, would he even recognize me as his equal? My parents might stand a chance, strong enough to command respect. But me? At my current level? I'd be as noteworthy as background noise at a rock concert.

That's why I can't afford to slack off. Every drop of sweat is an investment in a future where I don't just blend into the scenery, where I'm not just 'the other Wan.' So yes, Amanda, your concern is noted, but unless you can bench-press my ambitions, I'll kindly ask you to step aside.

I'm not here to meet expectations. I'm here to obliterate them. And that means training until my muscles scream, until the weights feel like feathers until my limits are nothing but a distant memory. Rest is for the complacent, and complacency isn't in my vocabulary.

"RYUJIN-SAMA, YOU MUST CEASE YOUR TRAINING AT ONCE!" Amanda's voice reverberated through the training hall like the clanging of a church bell.

"But —"

"I SAID NOW!"

"Very well, ma'am." I relent, setting down the weighted spear I'd been sparring with 

"Ye gods, you'll fall ill if you carry on like this, Ryujin-sama."

"That's highly unlikely. I've inherited a unique constitution from my mother. My inner mana — imbued with the essence of ice — regulates my humors and purges any imbalances. In the vernacular of our scholars, the cold mana coursing through my veins acts as a living phylactery against disease."

"Be that as it may, what would your betrothed, Suzune, think if she saw you in this state?"

"You mean, that Suzune? Our union is more a treaty than a wedding. It's a temporary alignment of family interests, unlikely to lead to lifelong commitment. She probably won't even venture here often, so why should it concern me?"

"Do you still hold a grudge over that false charge she leveled against you? Alongside that odd fellow, Pedro?" Amanda furrowed her brow, then shifted her tone. 

"Grudges are a waste of energy." I dismissed with a wave. "Those who cannot face me in an open contest resort to petty schemes. It's the refuge of the weak — skulking in the shadows, manipulating events rather than confronting them head-on."

(A|N: Ryujin and Ryuuka — aka Ester — have strikingly opposite temperaments. Ryujin abhors manipulation and values directness while Ester isn't above pulling the strings behind the scenes to ensure Ryujin's success. This dynamic should add an intriguing layer to their eventual romance.)

"That's good... good to know you don't harbor any affection for her… hehe, that lifts my spirits."

  "Why does it please you?" 

  "Oh, no particular reason, just, you know... personal preference."

"So, do you also think this engagement is pointless? After all, it detracts from the hours I could dedicate to training." 

"Ehh? Ryujin-sama, you training-obsessed nincompoop! Imbecile! Workout-wacko! Is your brain just a dumbbell lifting other dumbbells?"

Amanda let loose a string of spirited insults, her frustration mounting with each word.

After expelling her discontent in a colorful tirade, she stormed off, leaving me utterly bewildered. I scratched my head, still trying to pinpoint exactly what in our conversation had set her off like that.

◆◆

  After wrapping up my daily workout, I retreated to my room. Muscles weren't the only things that needed training, after all. Brains over brawn, they say. A substantial body without the intellect to wield that power was just a recipe for disaster.

"Ding-dong."

Ah, the doorbell. It must be Amanda. She probably baked another one of her delicious cakes.

"You may come in." 

The door swung open, and in stepped a figure radiating so much fury it was almost palpable. She was short, her red hair and blue eyes mirroring my own, but the resemblance stopped there. The expression on her face could only be described as incendiary.

My body instinctively shifted into a defensive posture. The air felt tense, every molecule seemingly charged with her ire.

"Nii-ni, explain this engagement nonsense! How dare you make such a life-altering decision without my consent!"