※ prologue ※

"Hey big brother, I can't sleep~" Amae said as she strolled into my bedroom.

My little sister wore an alluring midnight-black nightgown paired with thigh-high stockings — her pajamas. Small motes of warm light followed her like trailing fireflies. Amae chanted a command「Luminescence Spread」as soon she sat on my bed. The lights quickly scattered, permeating the room as it began to brighten in a few seconds.

"Want to join me tonight?" I blew out the candle since it was unneeded in the presence of my talented magician sister.

"I guess I'll take your offer," Amae replied in a smug tone, shrugging nonchalantly as she lay down and snuggled her cute face next to my chest. "I'll keep you company, only because you asked."

I laughed at her a-dork-able response.

"Anything bothering you, my dear sister?" I patted her head while she smiled in response. Her flowing, jet-black hair felt smooth between my fingers as I gently ran them down to her waist.

"That you're a 'Regular' and I am a 'Potential'." Amae then let out a deep sigh, drifting back into a sullen mood and held onto a pillow. "It's not fair. Even though we're going to the same school, we won't be in the same class. I want to be with you."

Temple Academy, a prestigious institution branded by countless experts and archmages across the world as the pinnacle for studying academic magic. Attending students were conferred ranks based on the results of an entrance exam.

A to C ranking were categorized as 'Potentials' while D to F were considered 'Regulars', with the latter being the lowest. Standing at the apex, 'S-rank' was the highest ranking a student can attain.

It is known that many of the famous magicians, such as XIV of Numerals Society, capable of using fourteen impressive variations of fire-elemental magic and Ade from Adventurer's Guild, an erudite archmage that single-handedly slain a Dragon were 'S-rank' prior to graduation.

It was unlucky for Amae that Temple Academy only permitted new coming students to be at the maximum of 'A-rank'. But understanding my sister's talents and magic potency, I have absolute faith that she will reach 'S-rank' by next year. There was no doubt about it.

"I do agree that it is unfair but that is to be expected from a magic-oriented university. Besides, you'll still see me after class is over." I said in a gentle tone, as though trying to placate a pouty child. "The only big change is that we won't be living across the hall from one another."

"That's not what I mean, big brother." Amae sighed again, probably because I missed her point. "It's the fact that you're starting at the lowest rank. It is an absolute insult to your skills."

"The results of the entrance exam was determined by magic abilities alone. The fact that I can't use magic meant that I am automatically placed in the lowest rank."

Amae is a 'Four-Attribute Magic' user.

In other words, she could adeptly cast all four main elements: fire, water, wind, and earth. The average magician could only use one element while talented users could use two or three at best. Compared to the world, Amae was a legendary magician by societal standards.

In stark contrast to my gifted sister, I possessed no potential for elemental magic. While my swordsmanship may reign at a Hero-tier level, I will most likely stay a 'Regular' for the next five years based on Temple Academy's hierarchy system.

"Still..." Amae muttered under her breath. "Everything we did for the past few years at the Adventurer's Guild... All that hard work... It's basically like starting at Bronze-tier again."

"I really don't mind." I held her right hand as our fingers interlocked by habit. "I am just glad that I could be with you. Besides, there's a possibility I could enjoy being a Regular as well. School ranking and social reputation are the least of my concerns when I have you with me."

Grandmaster was the one who raised us; training me in swordsmanship and Amae in magic. Although he was a tough and stringent teacher, we both gladly accepted him as our paternal mentor.

We lived in a secluded dojo from society, near the summit of the tallest mountain in the world known as Mt. Ains. It was about half an hour from the nearest town, with half of it involving hiking down a lengthy, serpentine set of stone-sculpted stairs.

"What if you are bullied?" Amae leaned in, our faces inches away from each other. "I heard many stories that Regulars are treated badly, perhaps even worse compared to the Adventurer's Guild because most students are nobles of the upper class. You know how haughty they can be."

"Of course I will handle it if people were to disrespect me. And if anyone is foolish enough to challenge me to a duel..." I glanced at my prized Katana, resting in its ornate black-sheath on a weapon stand. "...you know what happens, even if they may be an 'S-rank.'"

"I know, big brother. There's no one in the school that obviously stands a chance against you." Amae nodded in reverence to my forte. "But do let me know if you need help... I just... don't want you to end up hating school because of me..."

"I won't." I smiled, now understanding the root of Amae's distress. To think all this time, she was worried about my well-being. "Thanks for caring about me, I love you."

I love her. I really do.

"Say it again."

"Thanks for caring about me—"

"—Nooooooo."

"Just kidding." I chuckled at her expression and then switched in a serious voice, gazing deeply into Amae's navy-blue eyes. "I love you, my dear little sister. Let's have a memorable school life together."

"Yay-!" Amae let out a joyous cry as her lips blossomed into a beaming smile.

I patted her head again as she embraced me, nuzzling lovingly against my neck.

I thought about that fateful day when we became siblings.

We had been together constantly for the last decade. From basic house chores to mastering martial arts, neither of us could tolerate the idea of being apart, even it was for just one day.

Although Grandmaster may joke at how much of a siscon I was, he understood that we were like bread and butter. Our love was no secret to him. His eyes always twinkled with merriment whenever he teased us. Like him, most of the apprentices found it sweet and endearing, not shameful.

I moved to her right ear and whispered in a dulcet voice, "I told you from the first day when we vowed to become siblings and I'll repeat it as many times as you want, a sister's all I need."

Amae's cute face blushed into a lovable tomato-red.

"I-if you say it like that..." Amae's voice trailed off into a soft whisper. "I am going to be embarrassed you know... But I'm really glad."

"You know it's true," I gave her a quick goodnight kiss on the lips, "We should rest now. It's an important day tomorrow, it would be quite tragic for us to oversleep for the first-year orientation."

Amae laughed and nodded. Then she uttered the spell,「Luminescence Fade」. The bedroom dimmed into a faint warm glow, now perfect for resting. She hated sleeping in the complete dark.

My little sister loved being the little spoon whenever we slept together; nineteen years old but still acted like a little princess around her big brother. Well, I was not much better since I was only a year older.

I wrapped my right arm around Amae's delicate body. She held onto my hand in response, nuzzling her cheek against it. I felt her body shifting closer to me as she pressed her back against my chest.

Amae had a homely scent. It was a warm feeling that reminded me of how I could trust her completely with my heart and soul. And that she would never let me down.

My little sister was my other half.

Now that I thought about it, Amae grew into a fine young lady. Being slightly above my chest, her height did little to diminish how nubile her body had become. Her bosom had grown bigger and her butt felt more firm and rounded over the past few years.

The more I imagined her body, the more erotic my thoughts became.

Memories of Amae stripping and whispering naughty phrases enveloped my mind. Even though we made love many times in the past, I could only admire her beautiful curves every single time.

Suddenly, I felt her butt pressing lightly against my crotch and then paused. Based on past experiences, I knew she was waiting for me to continue.

I grinded against her butt, feeling it become hard. I thought I heard a muffled moan of pleasure, but it faded back into her normal breathing pattern.

A devious smile broke across my face. I realized she was playing 'The Sleeping Game' again.

I placed my right hand down into the bottom opening of her shirt-dress, gently caressing her tender thighs while I lifted the edges up, exposing everything bare up to her stomach.

I felt her legs gradually spread open in response, trying to fulfill her desires without being too obvious.

The smooth texture of Amae's stockings felt amazing to touch. I ran my fingers downward again, starting from the knee to her thighs, occasionally pausing to deliver delayed gratification. As I arrived at Amae's nether region, my fingers felt something lacey and amidst of that was a little ribbon.

I rubbed both corner gaps between her vagina and thighs with my index and middle finger, seeing if Amae would 'wake up' to this approach. But she endured the pleasure. To my success, I felt a moist indentation as my fingers reunited in the center.

"I think it's time for the next stage," I purred into her ear. There was no response. I secretly applauded Amae for her roleplaying.

I took her panties off and used the two fingers of my right hand to stimulate the area around her vagina. While purposely avoiding the center, I enjoyed the sensation of squeezing the two mounds together, then pulling them apart.

"N...mm..."

Amae's body twitched with pleasure as I continued to tease her. She began to squirm when I decided to lift my fingers away. I could tell her body was begging for more.

Then I moved my middle finger towards the center and into the slit.

"Gah..."

As Amae let out a sexy gasp, my finger was enveloped in a slimy wet sensation. I continue sliding in and out while remembering this tight feeling. That place was so hot, moist and indescribably soft. After a few minutes, Amae's whimpers turned to heavy panting as I pulled out and moved above to her clit.

"Wow, to think you are this wet," I whispered softly into her ears. "How about a special massage?"

I kneaded the little knob that peeked out from the top of the slit with my middle finger. As I continued rubbing, my left hand worked on playing with her beautiful breasts. I greeted her perky nipple with a light pinch and then flicked them gently back and forth.

"Mm...mm...ahh..."

I felt her chest rise up and down to my constant fondling. Her head tilted back into the crevice of my neck, leaking out a lustful moan in my left ear. In response, I showered her with kisses.

"Ahh!~"

"Not bad. I'll give you props for lasting longer than last time, but it's about time I finish this up."

I sat Amae up in between my legs with her back lying on my chest. I cupped my hand around her left breast and continued massaging it.

My other hand rubbed her clit faster and faster, massaging it in a constant circular motion while I forced her legs wide apart by locking them with mine. I could tell Amae was about to cum as her body twitched then trembled. Her moans were now blatant and filled with sexual desires.

"Mmm...ah...ah..."

With my ultimate finishing move, I nibbled her ear.

"Ahhhh!~"

Amae let out a sweet cry since I just attacked her ultimate weakness. The ear. A sensual spot that I saved the best for last.

"I-I'm coming, c-coming..."

Amae threw her head back with a jerk—

"—Ahhh-!"

After her body squirmed in a fervent manner for several seconds, Amae then turned around and collapsed her flushed face onto me. I felt her warm breath wafted repeatedly on my chest, before looking up with a combined expression of satisfaction and exhaustion.

"Did that feel good, my love?" I smiled, loving the pleasure I bestowed onto her.

"Yes..." Amae proceeded to hug me tightly. "But you are always the one teasing me..."

"Well, if I don't do that first, you will be sucking me off while I am asleep. Isn't that what you did last time?" I stuck out my tongue as she pouted at me for realizing her plan, "Besides, it's our last night together before we move to the dormitory. I heard they have strict rules on sleepovers."

"Stupid big brother," Amae pouted. "Now I am too tired to help you out..."

"Get some rest," I smiled and then lay back on the bed, opening my arms so she could join me. "Just treat me to something delicious tomorrow."

"Alright, I love you... big brother..." Amae replied tiredly and collapsed beside me, her eyes struggling to remain open.

"I love you too, dear sister." I smiled and leaned over, covering Amae's lips with my own.

Amae lifted her head and kissed back. She then muttered something under her breath but I could not understand it. Knowing her personality, I think she said something along the lines of I'll find a way to continue our kiss streak.

As my sister fell into a deep sleep, I took some time to ponder about our upcoming quest, requested by Mari — the Guild Master of Adventurer's Guild in Libertea.

After all, we did not enroll in Temple Academy to reap its positive benefits or form powerful connections. Those were the least of our concerns.

Our mission was simple; to act as spies and uncover evidence of the Headmaster plotting a World Domination.