Rin Tohsaka possessed 40 main magic circuits and another 30 auxiliary ones.
Yet, sometimes, fewer circuits didn't necessarily mean less power.
Take for instance the Fifth Magician, Aoko Aozaki. She only had a modest number of circuits, but they operated on an entirely different level.
Her magic circuits had superior rotation speed, structural durability, mana quality, and efficiency.
Just activating them produced sonic vibrations, and her mana surged through her body faster than blood.
She was feared for her signature high-speed casting style, a phenomenon nicknamed "infinite rotation."
When this human artillery cannon went all out, the destruction she left behind was staggering.
"Hngh…"
Kirisu Mafuyu grimaced as she focused, trying to sense the intense magical energy Kurosawa Ren was channeling into her body.
The mana felt raw and potent—like a living force brimming with vitality—and surged through her veins, flushing her porcelain skin with warmth and a deep, telltale blush.
After a few moments, the prolonged close contact proved too much.
Her breath came in hot gasps, and she hastily pushed Ren's hands away.
"N-No, I can't… Your mana is just… it's too hot—it's making me dizzy."
Ren gave her a helpless smile. "Sensei, you make that sound way more seductive than you mean to."
Flustered, Kirisu snapped back, "Don't make such inappropriate comments! I'm your teacher."
She straightened herself, trying to restore her usual cool and composed demeanor.
"As an educator, it's my duty to guide students to properly develop their talents."
"And yet, Sensei, you're not really good at this." Ren sighed. "You still haven't grasped the basics after all this time."
"Are you calling me stupid?!"
Kirisu's crystal-blue eyes widened in disbelief. Being openly mocked for her intelligence by one of her own students was a new kind of humiliation.
"You're the one who hasn't taught me well. Just give me a little more time and I'll master it!" she protested.
Ren rolled his eyes and stood up. "Sure, keep telling yourself that. I'm done here."
"W-Wait! You're seriously leaving? That was my first time...!"
Kirisu looked panicked and embarrassed as she grabbed at his sleeve, her voice barely above a whisper.
"I'm cooperating, okay? Isn't that enough?"
Ren turned back with a glint in his eye. "No take-backs. Once you agree, you follow through—no regrets."
"…Fine, I get it."
Biting her lip, Kirisu reluctantly nodded. Despite the overwhelming embarrassment, she knew she had little choice.
She needed magical protection—especially with how dangerous the world had become.
"Alright then. Hold my hand."
Ren took her delicate hand once more and, without warning, kissed her lips softly.
"Mmm—?!"
Kirisu's body tensed in shock. Her first instinct was to push him away.
But the moment their lips met, the magic within her started to surge—faster, stronger.
That elusive sensation she'd been trying to grasp suddenly felt within reach.
"Stay calm," Ren whispered against her lips. "Focus. Feel your magic circuit open."
The sheer pressure of Ren's overwhelming mana coursing through her unlocked something.
Click.
It was like a switch had flipped inside her.
A warm rush of power filled her chest, followed by a sudden clarity.
Her blocked magic circuits were fully open now.
An entirely new world had just unveiled itself to her.
"You're learning fast."
Ren smirked and leaned in to continue, but Kirisu shoved him back.
Face flushed a deep crimson, she curled her legs beneath her, knees pressed to her chest.
"I'm still your teacher, dammit!"
"And we're just having a very advanced academic discussion," Ren said innocently.
But they both knew that kiss had changed something.
For the rest of the day, the two were immersed in the mysteries of magic—one teaching, the other teasing, and both pushing boundaries in more ways than one.
The Next Morning
Kurosawa Ren slung his backpack over his shoulder and stepped out the front door, only to find Utaha Kasumigaoka waiting patiently at the gate.
"Good morning, Ren-kun~"
Today, she was dressed sweet and demure in a white sailor-style blouse, paired with a brown pleated skirt that reached below the knees. Her legs, wrapped in sheer black tights, subtly shimmered under the sunlight.
The conservative outfit did little to hide her stunning figure—especially her prominent bust that seemed to defy the bow-tied uniform blouse.
"Morning," Ren replied, falling into step beside her.
As they walked, Utaha casually took his arm and clung to it, pressing her body close with practiced intimacy.
The soft warmth of her skin and the gentle rhythm of her movement brought back vivid memories of their time together just days earlier.
"Ren-kun, I hear you've been quite the campus heartthrob lately," she said, her voice teasing.
Though she'd been out of school recently to finish a manuscript, Utaha had kept tabs on everything through the class group chat.
Apparently, her boyfriend was attracting girls like a magnet.
"I even saw Kitagawa go shopping with you yesterday," she added.
"You're jealous?" Ren raised an eyebrow with a smirk.
"Of course I am." Utaha puffed out her chest with pride. "I'm your real girlfriend."
Her ruby eyes sparkled with confidence. "And don't worry, junior. I've got something very special planned for you today."
Chapter: Double 10-Rolls and Desk-Side Flirting
Ren slid an arm around Utaha's slender waist as they approached campus, earning a wave of attention.
Whispers followed them like a trail.
"Dude, it's him again. And he's got his arm around Utaha-senpai this time!"
"Damn, he's always surrounded by beauties."
"Didn't he go out with Fujiwara yesterday? Or was it Kitagawa?"
"This guy's like some real-life harem protagonist!"
At first, people had gossiped behind his back. But lately, the vibe had shifted from jealousy to admiration.
Beneath a cherry blossom tree near the school gate, Jian Qiming stood silently, arms crossed.
Her eyes narrowed slightly as she saw Ren walking with Utaha, hand on her waist, laughing effortlessly.
A flicker of something stirred in her chest—frustration? Longing? She wasn't sure.
Beside her, Misaki Mizuki peeked out from behind a post.
"Are you mad at Ren-senpai…?"
"No!" Qiming snapped. She turned abruptly and walked toward the school.
They were just boyfriend and girlfriend. She had no right to feel like this.
But after all the life-and-death situations they'd faced together, seeing him cozy up to someone else just… hurt.
Not far away, Kato Megumi and Kitagawa Uimu exchanged tight-lipped glances.
Now that Utaha—the actual girlfriend—was back in the picture, everyone felt the pressure.
In class, Kirisu Mafuyu had finally returned after her mysterious sick leave.
"Good morning, everyone. I've fully recovered and I'm glad to be back," she said with a warm smile.
Today, she wore a crisp gray lady's suit that hugged her curves perfectly. Her skirt was tailored tight at the hips, and her long legs were wrapped in thick black pantyhose. She wore modest gray heels.
Her dignified beauty drew a round of cheers from both boys and girls alike.
But under the podium, Ren sat back and made a small, subtle hand gesture.
Kirisu, mid-lecture, caught it—and instantly turned beet red.
Her body trembled slightly. Her blue eyes seemed glazed with an embarrassed haze, as if remembering exactly what happened yesterday.
Ren chuckled silently.
Flirting with Mafuyu-sensei in class? Way more fun than behind closed doors.
Grinning, he tapped open his mobile gacha app and opened the summoning interface.
"Let's go—double 10-roll draw. Let's see how lucky I am today."