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The air in the bedroom felt almost frozen.
Lucian looked at Yukino Yukinoshita, who had her back to him, wrapped tightly in the blanket like a cocoon, her body still trembling faintly. He let out a quiet sigh in his heart.
He had to go to Sobu High tomorrow morning. It was his first official day as both homeroom teacher and math instructor. Showing up late on day one wasn't exactly a great start. Even with his "genius-level intellect" to fall back on, his energy wasn't limitless.
"I really need to sleep."
Just as Lucian was about to close his eyes, a crucial thought suddenly crossed his mind.
Yukino had thrown all her changed underwear into the washing machine earlier, and when they bought new clothes, she'd somehow forgotten to get any replacements.
If those freshly washed clothes weren't taken out and dried soon… was this rich young lady seriously planning to go to school tomorrow without anything underneath?
At that thought, Lucian quietly lifted the blanket and got out of bed.
Hearing the movement beside her, Yukino's body stiffened slightly under the covers, her breathing almost stopping from tension.
But to her surprise, Lucian didn't come closer. He simply walked out of the bedroom.
On the balcony in the living room, the washing machine had already finished its cycle.
Lucian opened it and took out the clean clothes one by one.
The night breeze was a little chilly. Standing on the balcony, holding those two pieces of delicate, minimal fabric that still carried a faint scent of detergent, Lucian's expression turned a bit strange.
"What even is my life… A dignified exorcist, hanging a student's underwear out to dry in the middle of the night…"
He gave a wry smile, shook his head, and quickly hung them up. He even clipped them carefully in place, making sure they wouldn't be blown away, so they'd be completely dry by morning in the early spring breeze.
After finishing, he returned to the bedroom.
He climbed back into bed as quietly as possible, lifting the sea-blue blanket and lying down again.
But a new problem arose.
This single apartment didn't have much in the way of spare supplies. There was only one blanket, and only one pillow.
Even though the pillow was fairly large, it still felt cramped for two adults trying to keep a "safe distance."
Lucian edged himself as close to the side of the bed as possible, taking up just a tiny corner of the pillow.
But Yukino's long, waterfall-like black hair was simply too thick and too long. It spread across the pillow like a dark silk net, inevitably spilling into Lucian's side.
"Mmm…"
Not even two minutes after closing his eyes, Lucian shifted slightly in his sleep—and accidentally pressed down on a strand of her hair with his shoulder.
Yukino, still facing away from him, immediately let out a soft, pained sound.
The tug on her scalp forced her to turn around. Her deep blue eyes, tinged with grievance and a hint of accusation, glared at him in the dim light.
"Teacher Lucian… you're lying on my hair," she said softly, her voice barely above a whisper, with a trace of annoyance.
"Sorry, sorry."
Lucian quickly lifted his shoulder and carefully moved the strand of hair back to her side.
Five minutes later—
"Teacher… you're on it again."
"Ah, sorry. I'm used to sleeping alone. I moved without thinking."
...
Another ten minutes passed.
"Teacher Lucian! Please stop moving around…" Yukino bit her lower lip. This time, her voice carried not just irritation, but a faint, uncontrollable tremble.
Lucian froze.
Under the dim bedside light, he quickly noticed something off about her.
She was no longer facing away from him. Instead, she lay flat on her back. That cool, beautiful face of hers had somehow become flushed again, an unnatural heat spreading across her cheeks.
Her breathing was rapid, her chest rising and falling sharply. A fine sheen of sweat had formed on her smooth forehead.
Most importantly, the clarity in her deep blue eyes was fading fast, replaced by that same hazy, intoxicated look she'd had earlier—when she was affected by the hallucinogenic toxin.
"Yukino? You're not running a fever, are you?"
Lucian instinctively reached out to check her temperature.
But the moment his fingers touched her skin, an alarming heat surged through them.
Yukino suddenly grabbed his wrist.
Her fingers trembled slightly, her palm burning hot.
Under the blanket, her body shifted restlessly. That overwhelming emptiness born from intense craving was devouring the rationality she prided herself on.
"Hot… it's so hot…"
She murmured unconsciously, her moist eyes locked onto Lucian. A tear even slipped from the corner of her eye, forced out by her effort to endure.
Lucian's genius-level mind clicked into place instantly.
The succubus spirit's toxin!
As an extremely rare evil spirit, the poison released upon its death couldn't be completely purged in a single, physical "detox." It had a terrifying incubation period and could flare up a second time—especially at night, in close proximity, when hormones and physical presence intensified the effect.
"Damn it…"
He cursed under his breath.
No wonder she'd kept complaining about her hair being pressed earlier. It wasn't really about that—her body had become hypersensitive due to the toxin. Even the slightest friction was unbearable.
"Teacher Lucian…"
Yukino finally broke.
Under the overwhelming surge of the toxin, she was like a drowning kitten. She moved closer on her own, pressing her burning body against his.
Under the wide blanket, there was no distance left between them.
She lifted her stunning, flushed face, her eyes slightly red, looking at him with a mixture of shame and pleading.
That gaze said it all: Help me.
Feeling the soft, trembling body in his arms—and the intoxicating fragrance filling the air—Lucian fell silent for a moment.
He took a deep breath. The drowsiness he'd been suppressing for tomorrow's early class was completely replaced by another kind of fire.
"…Sigh."
He let out a helpless sigh, then pulled her slender, boneless body into his arms, a trace of resignation flashing through his deep eyes.
"Looks like I'll be teaching my first class tomorrow with dark circles under my eyes."
"If that's the case… then let's do it one more time. I'll completely rid you of the toxin."
…
The night grew deeper.
The clock's hands quietly pointed to 2 a.m.
In the hallway outside the master bedroom, a door opened soundlessly.
Kasugano Sora, dressed in a pink silk nightgown, rubbed her sleepy eyes as she stepped barefoot onto the cool wooden floor, drowsily heading toward the bathroom.
"Mmm… drank too much water…"
She yawned, about to pass the master bedroom—when she suddenly stopped.
In the stillness of the night, even the faintest sound was amplified.
Especially when she was standing right outside a door that wasn't particularly soundproof.
"Mmm… nn…"
A stifled, broken sound—like someone trying desperately not to cry out loud—leaked through the gap in the door.
Along with it came the rhythmic, unmistakable creaking of the bed.
Even if Sora had no real-world experience, as a hardcore otaku—and someone with certain improper thoughts about her own brother—she immediately understood what was happening inside.
Buzz—
Her mind went completely blank.
All traces of sleep vanished, replaced by an explosive mix of shock, humiliation, and intense jealousy.
"Pervert! Beast! Liar!"
She clenched her fists tightly, standing outside the closed door, her delicate black eyes practically blazing in the darkness.
Didn't he say it was just one night? Didn't he say there was only one blanket and nothing would happen?
And yet—
Her brother was actually… with that vixen… doing something so shameless… just a wall away!
"....."