It was not jealousy.
It was an observation. A flag on the field. A clear breach in protocol regarding acceptable workplace proximity, abuse of shared office resources, and—apparently—flicking someone's curls without consequence.
Katsuki had a list of things that made his blood pressure spike. Kai was usually number five.
This week, he was number one through four.
-----
He stepped out of his office with the intent to approve a court submission and make someone cry in the hallway for forgetting pagination rules. Instead, he found them.
Again.
Kai, perched on the edge of Hana's desk like a man auditioning for the role of "charming disruption" in an office rom-com no one asked for. One leg dangling. Sleeves rolled. Shirt slightly unbuttoned, like professionalism was a vague concept from a past life.
Hana, of course, was laughing.
Laughing.
Her head tilted back, the sharp corners of her mouth softened into something far too open, too warm for a firm that billed ¥150,000 an hour to clients who cried during quarterly reviews.
Katsuki's jaw locked. He strode toward them with purpose.
"Can you not hover over my assistant like a goddamn vulture?" he snapped, voice like a paper cut.
Kai didn't even flinch. Just looked up with the lazy arrogance of a man who'd never known stress. "Relax. I was just borrowing her for a moment."
"She's not a library book, Kai."
Kai tilted his head. "True. But if she were, I imagine she'd be the rare kind. The kind everyone wants but no one can keep."
Katsuki didn't blink. Didn't move. Just filed that comment in the absolutely going to set something on fire later section of his brain.
Hana rolled her eyes, back to her screen, fingers already moving. "You two are ridiculous."
"Hey, Sukehiro," Kai murmured, too close, too familiar, "want to help me with that merger proposal later?"
Katsuki answered before she could.
"No."
Kai raised a brow. "No?"
"She has work to do. My work."
Hana didn't look up. "I can handle both, boss."
He hated that answer.
Hated the way Kai's smirk spread wider like he'd just won a silent bet.
Katsuki stepped forward, dropped a file on her desk with a soft thud. "Your plate's full," he said, voice clipped. "And if it isn't, I'll find something to fill it."
Kai stood. All six feet of gleaming, smug problem in Ferragamo.
"Careful, Hasegawa. People might start thinking you don't like sharing."
Katsuki stared. No expression. Just enough intensity to make Kai raise both hands in mock surrender and saunter off like he hadn't just lobbed a live grenade into the middle of his day.
Hana sighed, already flipping open the folder. "You two are exhausting."
He didn't answer.
Because that wasn't jealousy.
It was just efficiency.
And a deep, abiding commitment to eliminating all unnecessary distractions. Like… Kai. And whatever emotional circus act he was performing in front of his assistant.
-----
It wasn't a one-off.
The next day, Katsuki caught them in the break room.
Kai, leaning too close over Hana's shoulder, pointing to her coffee like it held national secrets. Hana's smile was small, almost reluctant, but real.
Katsuki walked in and immediately redirected them both to unrelated administrative hell.
The day after that, it was the reception area. Kai—actual devil incarnate—had his fingers in her hair. Not overtly. Just a curl. Twirling it around like it was an inside joke.
It was not an inside joke.
It was workplace misconduct.
Katsuki, naturally, interrupted again. For compliance. Obviously.
Not because he wanted to remove Kai's fingers with office shears.
That night, he slammed a file onto his desk with more force than necessary.
Naomi, standing in the doorway with her usual unimpressed aura, raised an eyebrow. "Everything alright?"
"Fine."
"You've been on edge all week."
"I'm always on edge."
"Sure," she said dryly. "But this feels like edge with extra knives."
He didn't respond. Just flipped through a case folder with intensity meant for actual court
Naomi leaned a hip against the desk, slid another document across. "You know, they work well together."
His hand stilled.
She went on, blissfully unaware that his blood had just crystallized. "Kai never likes anyone. But Hana? He likes her. They make a good team."
Good team.
Sure. If the metric was prolonged eye contact and disrespecting boundaries.
"She's my assistant," he said flatly.
Naomi blinked. "I mean, technically—"
"She's not a resource to be passed around like a stapler."
Naomi paused. Then gave him a look. "You're aware you sound insane, right?"
Katsuki didn't flinch. He never flinched. Flinching was for people who didn't spend their days eating subpoenas for breakfast and dissecting contract clauses like battlefield terrain.
But Naomi's words hit like a perfectly timed cross-examination.
"You know, you look like you're obsessed with your assistant."
There it was. Just… lobbed at him like she was tossing out a weather observation.
Cloudy with a chance of delusion.
He stared down at the file, jaw tight, fingers steady. Too steady. The kind of stillness that came just before someone set a courtroom—or an office—on fire.
Obsessed?
Hardly.
He was a managing partner of one of the most selective firms in Nagoya. He was responsible for billion-yen clients, multi-jurisdictional litigation, and wrangling Kai's calendar when the idiot forgot his own birthday.
He didn't have time for obsession.
What he did have time for, apparently, was monitoring how long Kai hovered over her desk, noting the cadence of her laugh, and experiencing full-body irritation when someone else elicited it.
That was not obsession.
That was vigilance.
That was management.
That was ensuring efficiency in the workplace and preventing unauthorized use of company resources, i.e., his assistant's time and attention.
Katsuki exhaled through his nose, the sound sharp and clipped.
"I am not obsessed," he said, tone surgical. "I'm irritated."
Naomi, still leaning against his desk like she owned it, raised one unimpressed eyebrow. "You've assigned her three different case reviews, two filings, and a translation job this week. All while glaring at Kai like he touched your limited-edition fountain pen."
"He did," Katsuki said flatly.
"...Okay, bad example."
He finally looked up, gaze cold enough to freeze boiling water. "She's being distracted."
"Right," Naomi said, nodding slowly. "And the appropriate professional response to distraction is overloading her with work and passive-aggressively loitering in Kai's doorway like a neglected housewife."
He stared at her.
"I'm managing productivity."
"You're emotionally constipated."
Katsuki inhaled. Counted to four. Reminded himself that murder was still technically illegal, even if it was cathartic.
"I expect high standards," he said. "If she wants to be taken seriously—"
Naomi cut in smoothly, voice softening in that terrifyingly maternal way she used right before delivering a verbal assassination. "She already is taken seriously. Just not always by you."
Silence.
His jaw flexed. That was uncalled for. Inaccurate. Probably false.
He didn't even dignify it with a response.
Instead, he went back to the case file, eyes scanning lines he wasn't reading, because all he could picture was the look on Hana's face when Kai leaned in and twirled her hair like some smug, overconfident—
He shut the file with a clean snap.
"Anything else?" he asked, tone a blade sheathed in ice.
Naomi smirked, pushed off the desk, and headed toward the door.
"Yeah," she said over her shoulder. "Maybe get your own assistant to smoke with you next time. Might solve a lot of your problems."
He didn't answer.
He just stared down at the file.
Not because she was right.
Obviously.
But because if Hana did have time to flirt with Kai, she sure as hell had time to learn how to cross-examine him instead.
-----
Honestly, it was getting weird.
Hana had lived her life under many systems of chaos—academic chaos, emotional chaos, caffeine-induced 3 a.m. meltdown chaos—but this?
This was controlled chaos.
Weaponized chaos.
Corporate-grade surveillance packaged in a very expensive suit.
Because lately? Every time she so much as made eye contact with someone who wasn't Hasegawa Katsuki, the man materialized. Like an unwanted pop-up ad with eyebrows and a legal pad.
It was subtle at first. Barely noticeable. He started assigning her more work—fine, normal, expected. She was good at her job. Great even. Possibly superhuman. Whatever.
But then things started getting... weird.
Exhibit A: She was talking to Kai—Kai, who didn't count, because he annoyed her on a spiritual level—and within thirty seconds of her laughing at something (it wasn't even funny, it was a meme about merger clauses and sword fights), Katsuki was suddenly behind her, dropping a folder on her desk like he was King Arthur handing her a burden instead of a blade.
"These need revisions. By noon," he'd said, voice flat as a defibrillator.
Cool. Sure. Noon was a social construct anyway.
Exhibit B: She stopped a junior associate by the copier. Asked a perfectly reasonable question about a formatting error in the Takamura contract. They spoke for maybe two minutes—tops—and then boom.
Katsuki again.
"Update the arbitration glossary," he said, not looking at her. Just hovering, looming, judging.
"Wasn't that Naomi's job?" she'd asked, already opening her notepad with a sigh that could launch a thousand resignation letters.
"She delegated."
To who, Katsuki? God?
Exhibit C: She was helping Nakamura-senpai—an actual partner, mind you—navigate the firm's internal docketing system, which was older than most cryptocurrencies and somehow twice as fragile. They were literally mid-keyboard when she heard it.
That cough.
That presence.
That sudden atmospheric drop in temperature that meant Katsuki was behind her again, arms crossed, gaze like a cold front moving in over the Pacific.
"Do you have a minute?" he said, even though she very clearly did not have a minute. She had a laptop, a senior partner, and a righteous sense of indignation.
She went anyway.
And then.
Then—the most unhinged moment of all—she got a delivery. One tiny package. From a completely innocent online order. A waterproof notepad for her shower because, hello, her best ideas came mid-conditioner.
The poor delivery guy barely stepped into the lobby.
And yet there he was. Hasegawa. Appearing behind her like a demon summoned by barcode scanners.
"This isn't a mailroom," he said.
"It's a notepad."
He gave her a look.
"An idea notepad."
The look didn't change.
"For the shower."
Still nothing.
"Never mind."
He walked away without a word.
She stared after him, equal parts furious and… confused?
What the hell was going on?
It wasn't like she was slacking off. If anything, she was hitting deadlines faster. Managing his inbox better. Surviving his moods without homicide. She even re-alphabetized his deposition archives and didn't passive-aggressively label them "B for Bastard."
Yet somehow, every conversation, every moment of oxygen that wasn't spent entirely focused on him was a tactical offense punishable by extra assignments and existential dread.
She flopped back in her chair, stared at her to-do list, and counted the number of times he'd dumped something on her desk within thirty seconds of her speaking to another human.
Nine.
It was nine.
She scrawled "get exorcism" in the margins of her notebook.
Either she was losing it, or Katsuki Hasegawa had officially declared psychological warfare.
Fine.
She worked best under pressure anyway.
And if he wanted her attention that badly, he could at least admit it like a normal person.
Or tattoo "MINE" across her forehead and save them both the performance.