Chapter Text
Disclaimer: Detective Conan is the property of Gosho Aoyama. I do not profit from writing this fanfiction. This story contains spoilers for Detective Conan and includes quotations from the manga, anime, wiki, and other sources.
Never Say That I Was False of Heart
Chapter I
Miyano Shiho—currently living under the alias Haibara Ai—regarded the meal set before her on the dining table with thinly veiled suspicion.
It was a complete takeaway from Café Poirot: soft pumpkin gnocchi coated in a creamy béchamel sauce, paired with a vibrant garden salad, lightly dressed and scattered with parmesan. It looked innocent enough. Pleasant, even. But experience had taught her that unexpected kindness—especially when delivered by a certain detective—often came with strings attached.
This particular offering had been delivered, quite casually, by Kudou Shinichi during an unannounced visit to the professor’s house. He’d strolled in as if he owned the place, two neatly packed portions in hand.
Naturally, Professor Agasa had been ecstatic.
“Ai-kun, can we eat now?” the professor asked eagerly, practically bouncing on the balls of his feet as he hovered beside the table. His eyes were fixed on the meal like a man who’d just stumbled into an oasis after wandering the desert.
Shiho sighed, relenting. “Yes, Professor. Go ahead.”
So much for today’s attempt at healthy eating.
“Itadakimasu,” the professor declared joyfully, wasting no time before tucking in. His eyes lit up after the first bite. “Oh, this is delicious!” he said between enthusiastic mouthfuls.
Shiho picked up her fork with more restraint, spearing a piece of gnocchi and studying it as if it might reveal some deeper secret. As the creamy sauce hit her tongue, she felt the tension in her shoulders ease—annoyingly, it was good. Far better than she wanted to admit.
A few days later, Kudou showed up again. “Azusa-san accidentally ordered too many pumpkins for Poirot,” Kudou explained as he set the containers down. “They’re doing a whole themed week to use them up—pumpkin in everything. Gnocchi’s the most popular.”
This time, the gnocchi came in a rich Bolognese sauce, simmered with herbs and topped with fresh basil, accompanied once more by a side salad and a loaf of warm, crusty bread.
Next to her, Professor Agasa's reaction was exactly as expected — overjoyed and deeply appreciative. He accepted the food with the reverence of a man receiving sacred offerings, and wasted no time tucking in.
Shiho raised an eyebrow, folding her arms as she stared at Kudou. “So, you’re helping them out, are you? How very noble of you,” she said, her tone as flat as a sheet of glass.
Of course, she knew exactly what—or rather, who—he was actually interested in.
Bourbon.
Shiho had no doubt whatsoever that Amuro Tooru's presence was the real reason Kudou Shinichi had suddenly developed a suspiciously passionate appreciation for pumpkin gnocchi.
“You know, if you’re going to spy on Bourbon, you might as well admit it. It’s not as if the rest of us haven’t noticed.”
"Spying? That’s a bit dramatic.” Kudou replied.
She gave him a long, level look. “You're lurking at Poirot with the subtlety of a sledgehammer.”
He had the nerve to look affronted. “I’m keeping an eye on things. That’s different.”
“Really.” Her voice was dry enough to parch the air.
Kudou offered a casual shrug, entirely too relaxed for someone under scrutiny. “It’s not like he doesn’t know I’m watching him. This is a mutual arrangement.”
Shiho let out a breath and leaned back in her chair, arms folded. “Right. Mutual professional stalking. So reassuring.”
All of this had started not long ago. It began when someone they suspected to be a member of the Black Organisation appeared—subtly at first, like a shadow slipping into familiar places.
Bourbon. She’d heard of him long before she left the Organisation. A specialist in infiltration, known for his keen intellect and unnerving ability to extract information without ever raising suspicion. He blended in seamlessly, slipping between personas like changing coats.
Even Gin—who rarely gave compliments and never indulged in admiration—had once, with a trace of irritation, referred to him as “a great detective… like Holmes.” Coming from Gin, that single remark had carried the weight of a gunshot. It was all Shiho needed to hear.
Shiho still remembered their confrontation aboard the Mystery Express. At one point, she had genuinely believed she was going to die. Her heart had pounded like never before—cold and leaden, each beat echoing like the tick of a final countdown.
But then, just like that—Kudou’s plan had worked. With the help of Kaitou Kid, they had staged her death. A perfectly executed illusion. Smoke, mirrors, and misdirection—tricks worthy of the great thief himself. They had fooled Bourbon. More importantly, they had fooled the Organisation.
She had thought it was over.
But Bourbon hadn’t left. Instead, he had lingered at Café Poirot, taking up residence behind the counter with a smile and a cup of coffee, like he belonged there. Shiho had done her best to steer clear—keeping herself away from the café, away from him.
It was only later that Kudou confided the truth: Bourbon wasn’t with the Organisation. He never had been. He was an undercover operative from the Japanese Public Security Bureau, embedded deep within the Organisation to gather intelligence. Everything he’d done, every cold glance and calculated move, had been part of his cover.
Her first reaction had been relief.
One less enemy for her—and for Kudou. That alone was reason enough to breathe easier.
But once the initial tension had faded, she began to notice something else. Something subtler. Kudou seemed far too enthusiastic whenever he talked about Amuro Tooru, the alias Bourbon now used.
At first, she’d written it off as understandable. After all, Kudou was a genius. Someone who, back when he was still Kudou Shinichi, could have taught his high school teachers a thing or two. A mind that operated like clockwork, dissecting high-profile criminal cases with the ease most people reserved for breathing. Deduction was second nature to him—more instinct than skill.
And now?
He was trapped in the body of a seven-year-old. Forced to live as Edogawa Conan, a second-year elementary school student with a squeaky voice and a backpack far too big for someone who had once stared down serial killers and criminal masterminds.
He used to stand beneath flashing police lights, rattling off deductions with absolute confidence, surrounded by journalists and stunned officers.
Now, he sat in elementary school classrooms, learning basic arithmetic and practicing kana drills alongside children who still thought Santa Claus was real.
It must be maddening. Shiho had considered that more than once—how suffocating it must be for someone like him, pretending to be a child in a world that no longer recognised him.
She, at least, had the sanctuary of living with Professor Agasa. There, she could drop the façade and be herself. No pretending. No masks. They spoke as adults—exchanging ideas, sharing research, and living in a quiet companionship built on understanding and trust. The professor didn’t treat her like a child, nor did he expect anything more than her truth.
But Kudou had no such refuge.
He lived with the Mouris, surrounded by people who only ever saw Edogawa Conan—the seven-year-old boy detective. A clever child, yes, but still a child in their eyes.
He had no space where he could be truly himself.
She’d noticed that Kudou acted far more like himself when he was with the Detective Boys—so much so that even they found it strange whenever he tried to behave like a typical child around adults. But with Amuro—at least, according to Ayumi and the others—he didn’t have to pretend at all.
No childish mask. No effort to conceal the brilliance beneath the surface. They spoke as equals. No roles. No deceptions.
Of course Kudou would gravitate toward someone like that—someone who could match him intellectually, who saw through the same illusions and half-truths. Someone like him.
Both of them were living double lives. Triple lives, in Amuro’s case. Each locked into roles where their true identities had to remain hidden—carefully concealed for survival. That alone was a powerful point of connection, one that most people couldn’t even begin to understand.
And then, there was the matter of proximity.
With Café Poirot situated directly beneath the Mouri Detective Agency, Kudou no longer needed to invent excuses or travel far. There was no need to sneak out or fabricate stories about where he was going. Just a simple walk down a flight of stairs, and there he was—face to face with someone who truly saw him.
At first, Shiho told herself it was nothing. A mere curiosity, nothing more. A passing fascination that would surely fade. Kudou had always had a tendency to fixate on things—and on people—when they posed a challenge. And Bourbon, or Amuro, or whoever he was at that moment, was a walking enigma. A puzzle with too many missing pieces.
But as time passed, Kudou did not grow bored. Far from it. He became... invested.
Their interactions deepened, spilling beyond the confines of Poirot Café. They found themselves wandering through bookstores together, their conversations lingering over rare editions and detective novels. They shared quiet afternoons exploring other small haunts around town—places where the weight of their hidden lives could momentarily lighten.
Shiho watched all this unfold with a mixture of curiosity and unease. Kudou’s growing attachment to Amuro was no longer just a passing phase—it had become something far more complex.
And then, one day, Kudou dropped a bomb.
“Do you want to play football tomorrow, Conan-kun?” the Detective Boys asked, their voices cheerful as they walked home together after school on Friday afternoon.
It was the beginning of February, and the cold bit at the air with quiet persistence. Shiho tugged her coat tighter around her, the chill settling into her bones despite the weak sunlight overhead.
“I’m sorry, guys, but I’m going to the Sherlock Holmes exhibition tomorrow,” Kudou replied, hands tucked into his coat pockets, his tone as casual as if he were talking about the weather.
“Eh?” Genta blinked, clearly taken aback. “You didn’t say anything about that before!”
“Why didn’t you tell us?” Mitsuhiko protested, frowning. “We’d have wanted to come too!”
“We do want to go,” Ayumi added, looking slightly betrayed.
“Sorry, but the tickets are limited,” Kudou said, managing to look both apologetic and slightly amused. That liar, Shiho thought, narrowing her eyes at him from the side. “We can play football another time. Anyway, it’s still a bit too cold, don’t you think?”
"I saw on the news there’s a snowstorm in Sapporo!” Genta piped up suddenly, as if reminded.
And just like that, the conversation shifted. The children quickly forgot their disappointment and began chatting animatedly about snowstorms and whether it might snow in Tokyo soon.
When they parted ways, Kudou followed Shiho to Professor Agasa’s house, his hands buried deep in his pockets as he walked just behind her, the sound of their footsteps muffled by the cold. It was early February, and the chill of the evening nipped at their skin. Shiho tightened her coat around herself, her breath puffing out in small clouds as they entered the house.
Professor Agasa was in the back room, immersed in his usual tinkering, the hum of machinery a familiar background noise. She hung her coat up by the door, glancing over at Kudou, who was already leaning against the wall.
“So, Sherlock Holmes exhibition?” Shiho asked, her voice cool, though a small spark of curiosity ignited behind her eyes. “And I suppose you’re going with him?”
She didn’t need to say his name—him was Amuro, and that was more than enough.
Kudou, completely unbothered, gave her a small shrug. “We’re dating now.”
He said it so casually, as though it were no more important than mentioning the weather.
Shiho blinked, staring at him as if she’d just heard him say he was planning to fly to the moon. Her mind took a moment to catch up with the absurdity of what he had just said. Her first reaction was pure, unfiltered surprise, but then, just as quickly, a dry smile tugged at the corner of her mouth. Only Kudou Shinichi could make something like that sound so… trivial.
With a quick flick of her hand, she struck him on the arm.
“Ow! What was that for?” Kudou grumbled.
“You’ve got the nerve to ask that?” Shiho said, her voice dripping with sarcasm. “You, of all people—dating him? Have you gone completely mad?”
Kudou shrugged, unphased. “It wasn’t like I planned it. It just happened."
Shiho stared at him for a moment longer. “You really do have a knack for getting yourself into the most ridiculous situations, don’t you?" she muttered. Her amusement faded quickly, replaced by a more sober thought. She suddenly realised what it meant. He knew.
“He knew,” Shiho whispered, almost to herself, the realisation hitting her with the force of a freight train.
It wasn’t a question. It was a statement. Because no one, not even Bourbon—especially Bourbon—would get involved with Kudou without knowing exactly who he was. No way.
Kudou caught her expression, his own shifting slightly. “I didn’t tell him,” he said quietly. “He figured it out on his own. He put the pieces together.”
Shiho didn’t know whether to be impressed or terrified. But the one thing she definitely wasn’t was surprised. This was Bourbon they were talking about—a man who could see through lies and fabrications with a terrifying clarity. It was no wonder he’d uncovered the truth.
She resisted the urge to smack him again. “You’ve got some nerve,” she muttered, but there was a flicker of amusement in her eyes. “I hope you know what you’re doing, because this is the sort of thing that tends to blow up in your face.”
And what was Bourbon doing?
Shiho found herself pacing the living room, arms crossed, trying—and failing—not to spiral into incredulity. It wasn’t just Kudou who was at fault here. She couldn’t, in good conscience, place the blame entirely on him. Because Bourbon—Amuro—or whatever his real name was—was just as responsible.
Wasn’t it enough that he was an undercover agent, already walking a knife’s edge within the Black Organisation? That he spent his days playing the role of a loyal dog to murderers and masterminds, feeding the Public Security Bureau whatever scraps of intelligence he could risk smuggling out?
And now, this? What was he thinking? Scratch that—what were both of them thinking? Had they cracked under the pressure? Was this what happened when you buried yourself too deep in deception for too long—when you forgot where the cover ended and the truth began?
Shiho sank onto the edge of the sofa, one hand pressed to her temple, as if the act of thinking too hard about it might give her an aneurysm.
Opposites might attract when you were working with magnets. But with people? People were messy, irrational, dangerously unpredictable. There were sayings—opposites attract, birds of a feather flock together—and both had their moments of truth.
But in her experience, it was the shared similarities that truly pulled people together. Shared experiences. Shared burdens. Shared intellect.
And that, unfortunately, was exactly what tied Kudou and Amuro together.
They were, despite surface differences, remarkably alike.
Both brilliant. Both obsessive in their pursuit of truth. Both able to read a crime scene—or a person—within moments. Calculating. Ruthless, when necessary. Always ten steps ahead, and always alone at the top of the chessboard.
Of course they’d be drawn to each other.
Shiho frowned.
She could see it. She hated that she could see it. Amuro possessed a mind as sharp and dangerous as Kudou’s own, and she had no doubt that was where the initial spark had started. Intellect attracted intellect. And while Kudou had been isolated, surrounded by people who only saw the mask of Edogawa Conan, Amuro had looked at him—and seen the real person underneath.
The fact that Amuro was also an absurdly good-looking man didn’t hurt. Those golden eyes, that calm confidence, that effortless charm—he could make anyone lower their guard if he wanted to.
It made perfect sense.
But that didn’t mean she agreed with this. Emotional attachments were already dangerous under normal circumstances, but this?
Kudou sat down on the sofa across from her, leaning back like he didn’t have a care in the world. His posture was relaxed, but his eyes were watching her carefully.
“Hey, Haibara,” he said quietly. “Are you all right?”
“You do like living dangerously, don’t you?” she grumbled, not looking at him.
Kudou blinked, feigning innocence. “What? No. Not really.”
Shiho let out a long, tired sigh—the sound of someone whose patience was being tested on a near-spiritual level.
“I swear, you’re insane if you think this won’t come back to bite you,” she muttered.
“There’s a risk in everything,” Kudou said finally, his tone more careful now.
“What did I ever do to deserve this?” she muttered to herself. It was rhetorical, but the question was still laced with genuine exasperation. She wasn’t sure if she meant Kudou, or Amuro, or just the entire absurd web of her current life.
Kudou, predictably, just grinned. “Saved me, multiple times? Joined me in a life-threatening conspiracy? Became one of the few people I trust?”
Shiho rolled her eyes. “I was being sarcastic.”
“I know.” His voice softened. “But you’re also one of the only people I can actually talk to about this.”
That stopped her for a second. Just a second.
She looked away, annoyed with how familiar this all felt. Kudou doing something reckless. Her calling him out. Him justifying it with logic and emotion all wrapped together in that annoyingly sincere way of his.
“You're unbelievable,” she muttered, shaking her head. But despite herself, a hint of a smile tugged at the corner of her mouth.
There was a trace of affection in her voice. She couldn’t quite help it.
Kudou’s eyes softened a little as he caught it, but he wisely didn’t comment on it.
Instead, he leaned back, laced his fingers behind his head, and smirked like he hadn’t just upended her entire afternoon. “Yeah, well. You’re still talking to me. That must count for something.”
Shiho exhaled through her nose, a soft sound somewhere between a sigh and a snort. Her arms were still crossed, her expression unreadable—but the corner of her mouth twitched ever so slightly.
“It counts as me tolerating your questionable life choices,” she said flatly. “Don’t push your luck.”
They sat in silence for a while longer, the hum of Professor Agasa’s machines buzzing faintly in the background. Outside, a cold February wind rattled the windows.
And for a moment, just a moment, things felt almost... normal.
Author’s Note:
The title is taken from Shakespeare’s Sonnet 138: O, never say that I was false of heart.
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