Reincarnated in the World of High School DxD

Half a month had passed since the Holy Sword incident.

The sweltering summer days clung to Kuoh Academy like a damp curtain, but the early morning air still carried a crisp chill. Kazuki jogged toward the old school building's training grounds, his breath steady, muscles warm.

As he rounded the corner, he found his usual training companions already waiting.

"Mornin', Kazuki-senpai!" Issei grinned, sweat already glistening on his forehead despite the cool air.

"Good morning, Kazuki-san," Asia chirped, her hands clasped nervously.

"Senpai, you're late," Yumi teased, her twin blades—[Sword of Betrayer]—glinting at her hips.

Kazuki nodded, rolling his shoulders. "Morning, Issei. Asia. Yumi."

Since the Holy Sword crisis, Issei had begged Kazuki to join his dawn training sessions.

What began as a solo routine had expanded into a ragged group effort—Yumi's relentless drive, Asia's quiet determination, and Issei's loud desperation to close the gap between himself and the monsters they faced.

Not all members of Rias' peerage showed up consistently, but these three never missed a day.

"Let's start. Asia—barrier," Kazuki ordered.

"Yes!" Asia raised her hands, and a shimmering dome of light erupted around the field. Her magic had grown steadier since joining the peerage, though her gentle nature still leaned toward defense over offense.

"Issei, Yumi—Sacred Gears out."

Two pulses of energy crackled in response. Issei's left arm erupted in crimson scales as [Boosted Gear] activated, its emerald gem throbbing. Yumi drew her X X-shaped blades, the [Sword of Betrayer] humming with chaotic light—one edge blazing holy, the other dripping miasma.

"Okay, any time now," Kazuki smirked, cracking his knuckles.

Yumi moved first. As a Knight, her speed was unmatched, she closed the distance in a blur, swords arcing toward his ribs. But Kazuki pivoted, using her momentum to launch himself at Issei instead.

"Shit—!" Issei barely raised his armored forearm in time. Kazuki's fist, reinforced with demonic energy, smashed into the gauntlet. The impact reverberated like a gong, sending Issei skidding backward across the dirt.

"Gah—!"

"Eyes up, Issei," Kazuki growled, already behind him. A chop to the back of the skull sent the boy face-first into the ground.

Asia blew her whistle sharply., "First round—over!"

Kazuki stepped back, arms crossed. "You recovered fast after the punch. Good. But dropping your guard to look for me? Pathetic. My speed today was Freed-level. If you can't handle that, you'll die the next time we face him."

Issei groaned into the dirt. "…Yes, senpai."

"Yumi." Kazuki turned, his gaze sharp. 

"You're relying too much on those swords. Yeah, they're powerful. But if your opening strike gets dodged, you're defenseless."

Yumi stiffened, her grip tightening on her blades. "I… understand."

"Before the Sword of Betrayer, you adapted. Created demonic blades on the fly—wind for speed, earth to trap enemies. Now you're stagnant." He stepped closer, voice lowering. "That sword's a tool, not a crutch. Use it smart."

"I—I thought mastering the Sword of Betrayer would…"

"Mastery isn't an obsession," Kazuki cut in, his demonic energy crackling like a live wire. "That sword's a tool, not a crutch. Next time you miss, pivot. Adapt. Or you'll die choking on your own hesitation."

The training dragged on, brutal and unrelenting. Issei's [Boosted Gear] gauntlet gleamed under the dawn light as he lunged, only to eat another dirt sandwich courtesy of Kazuki's boot. 

"Ten seconds," Kazuki sneered, pinning the wheezing boy beneath his heel. "That's all your Gear needs to double its power. But if you can't survive those ten seconds, you're just a glorified punching bag."

By the time they limped back to the clubroom, even the ever-cheerful Asia looked ready to collapse.

Kazuki Fuwa dismissed the others with a grunt, steam rising from his sweat-drenched shirt as he stalked toward the showers.

The water scalded his skin, washing away the grit and frustration. Kazuki braced his hands against the tile, head bowed as the heat seeped into his muscles.

Then—the click of the door.

Soft.

Deliberate.

Before he could turn, weight pressed against his back—full, supple curves slick with soap.

A familiar perfume cut through the steam. "Rias," he growled, though his body betrayed him, tensing at the glide of her nipples against his spine.

"Mmm, full marks~" Rias purred, her hands sliding around his waist. Her breasts molded to his back as she dragged a soapy loofah down his chest, lower—"You worked them hard today. Let me… reward you."

"Tch. This your idea of subtlety?" Kazuki's voice was rough, but his pulse roared as her fingers found his abs, trailing lower—

"Subtlety's boring," Rias breathed, her lips grazing his ear. 

"Besides, watching you break those brats…" Her thigh slid between his legs, "—it's hot."

With those words, Rias's hands, which had been caressing his chest from behind, began to slowly move downward. From his chest to his stomach, and then further down to his groin. Finally, she grasped his fully erect cock with both hands.

"Kuh...!?"

"Ah, it's so hard, Kazuki..."

Thanks to Rias's actions, Kazuki's body was fully prepared for what was to come. With each stroke, pre-cum spilled out, making wet, squelching sounds as it soiled Rias's hands.

"Ahh, ahh..."

"Haa, haa... feel good, Kazuki..."

Rias trailed her tongue along the nape of his neck from behind. The ticklish sensation of her tongue made Kazuki twist his body involuntarily.

"Rias... I want to kiss you."

"Kazuki?... Mmm, I want to too."

"I want to see your face while we kiss. Is that okay?"

"Of course... it's fine. Turn this way, okay?"

Rias loved kissing him so much, so...

Whether it was a deep, tongue-entwining kiss, a pecking bird-like kiss, or a soft, barely-touching kiss, she adored them all. Whenever they kissed, Rias's face would light up with genuine happiness.

Kazuki loved seeing that expression on her face, and he had lost count of how many times their lips had met since their first kiss.

~~~~~~~~~~~~~~

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