The Scarlet Devil Mansion had grown tremendously since the worlds merged.
Countless fairies now lived and worked throughout the vast estate.
As Izumi wandered through the halls, many of them hurriedly stopped to bow.
"Good day, Lord Izumi!"
He simply waved them off with a smile.
"Relax. Carry on."
With that, he continued his leisurely exploration.
Although the mansion technically existed within his domain, he had rarely taken the time to properly look around it himself.
Eventually, he arrived at the entrance leading underground.
A certain resident immediately came to mind.
The corners of his lips rose slightly.
Without hesitation, he descended toward the mansion's famous underground library.
The library door stood open.
As soon as Izumi stepped inside, a familiar voice echoed from somewhere among the endless bookshelves.
"Sakuya?"
"Just leave the tea there."
"I'll drink it later."
"I'm working on a new spell right now."
"I don't have time."
Hearing that voice, Izumi smiled.
"Patchouli."
The voice suddenly stopped.
A moment later, a purple-haired girl wearing a large crescent-moon hat peeked out from behind a towering stack of books.
Her eyes widened in surprise.
"Izumi-kun?"
"When did you get here?"
"Did something happen?"
As one of the researchers who had occasionally collaborated with Sayaka Kirasaka and the Academy City's magical development projects, Patchouli had met Izumi numerous times before.
Still, his sudden appearance here caught her completely off guard.
More importantly—
She wasn't exactly sure how she felt about him.
On one hand, she respected him deeply.
He had saved Gensokyo.
He had cured her chronic asthma.
And he had changed countless lives.
On the other hand...
She had witnessed far too many girls becoming involved with him.
As far as Patchouli was concerned, Izumi was the definition of a hopeless womanizer.
Of course, she would never say that to his face.
Looking at the frail-looking witch sitting among mountains of books, Izumi felt an overwhelming urge to tease her.
There was simply something about a quiet, sickly bookworm that awakened the mischievous side of human nature.
He walked over and glanced at the magical formulas spread across her desk.
"Oh?"
"Researching modern magic?"
"Need any help?"
Patchouli immediately became vigilant.
A warning bell practically rang inside her head.
There was a saying:
When someone is unusually nice, they're usually plotting something.
She narrowed her eyes.
"Izumi-kun."
"Is that really why you came here?"
"Shouldn't you be spending time with your girlfriends instead?"
The suspicion in her voice was impossible to miss.
Izumi laughed.
"My girlfriends?"
"Aren't you one too?"
The moment those words left his mouth, Patchouli's face turned bright red.
"W-What are you talking about?!"
"Don't make jokes like that!"
"If you don't have any business here, please leave."
She immediately attempted to chase him out.
After all, she still remembered the warnings she'd received in the past.
Never stay alone with Izumi for too long.
Before you know it, he'll drag you into his pace.
At the time, she'd dismissed those words as exaggerations.
Now?
She wasn't so sure anymore.
Izumi merely shrugged.
"I'm only telling the truth."
"The moment you stepped into my world, you were already someone important to me."
"No amount of denial will change that."
Patchouli's face grew even redder.
"That doesn't count!"
"I never agreed to anything!"
"You can't just decide things on your own!"
"And if you keep saying strange things, I'll report you to Sayaka!"
Her protests only made Izumi laugh harder.
The poor witch looked completely flustered.
Seeing her reaction, he finally relented.
"Relax."
"I'm just teasing you."
"Honestly, you make it far too easy."
Patchouli glared at him.
"You're the worst."
"That's what everyone says."
"And yet you're all still here."
"I wonder why."
"Because nobody can get rid of you."
"That sounds about right."
The two continued exchanging playful remarks.
Although Patchouli acted annoyed the entire time, the atmosphere gradually relaxed.
Eventually, they sat together discussing magic theory, spell structures, and the modernization of traditional sorcery.
Once the conversation shifted to research, Patchouli became completely absorbed.
Her eyes lit up.
Questions led to answers.
Answers led to debates.
And before either of them realized it, several hours had passed.
By the time Patchouli finally noticed the time, she let out a frustrated groan.
"I was supposed to finish my spell today..."
Izumi laughed.
"Then I should probably stop distracting you."
"Good."
"Please do."
"Though..."
Patchouli hesitated.
"...thanks for the advice."
The spell framework he'd suggested had solved a problem she'd been stuck on for weeks.
Izumi stood and stretched.
"Anytime."
"I'll come visit again."
Patchouli immediately frowned.
"Please don't."
"That's a cruel thing to say."
"It wasn't meant kindly."
"Haha."
With a final laugh, Izumi turned and left the underground library.
Behind him, Patchouli watched the door close before letting out a long sigh.
Then she glanced at the notes scattered across her desk.
A small smile appeared on her face.
"...What an impossible person."
And before long, she returned to her research.