There are some things you don't forget: how to ride a bicycle, turn a wrench, or hold a knife strong enough that it can't be easily pried from your grip.

It was 5:30 on a Friday afternoon in Suzaka, just across the river from Nagano City. On a quiet street just about a kilometer from Suzaka Station was a six-unit apartment building. The unit furthest to the left belonged to Amari Kagura, a graduate student at Shinshu University. I stood in front of Amari-san's door with a grocery bag slung over my shoulder, carrying milk, butter, and vanilla extract. We'd planned to do some baking that night for a party over the weekend, and Amari-san had asked me to bring some ingredients for icing. Instead, I'd found her door ajar, with obvious toolmarks on the knob.

I lowered the grocery bag slowly, trying not to make a sound, and I drew a small, five-centimeter knife from my waistband. I held it with the blade pointing downward in my fist, and that feeling was all too familiar. Years ago, whenever a strange sound woke me up at night, I'd reach for that knife and carry it in hand as I looked around my home and satisfied myself that no one was coming. It had been a long time since then, but I still carried that knife with me every day, and as I nudged Amari-san's tan-colored door open with my pinky finger, the knife in my opposite hand felt comfortable and safe. Perhaps, in truth, I had never let go of it.

I pulled the door open slowly and stayed behind the threshold. The lights were off. The main room and the kitchen were as dark as a graveyard at midnight, and her alarm system had been disarmed. Knife still in one hand, I checked my phone with the other. She still hadn't called me back or answered my text messages. Perhaps it was still too early, but I smelled something foul in the air, and in a matter like this one, there was no time to waste. I flipped through my contacts, and I made a call. He picked up right away.

"Well, well, look who it is," he said with juvenile impishness. "I never thought I'd see the day where you called me for a change. What's the occasion?"

"I need you," I said quietly, watching the dark doorway.

"I'm sorry, can you say that again, please? I'm ready to record now."

If I could've glared at him through the phone, I would've, but I had to keep calm and steady. "I'm at my colleague's home. She didn't show up to the lab today, and now I'm at her doorstep. The unit's been broken into, and she's not answering her phone. I'll say whatever you want some other time. Right now, I need you."

The other end of the line went quiet for a moment, and after a pause, he said, "I'll be right there."

I thanked him, hung up, and sat down beside my bag of groceries. In spite of the danger Amari-san could be in, my heartbeat was steady, and I could be patient. Like with that knife, it'd been a long time since I relied on Kudo Shinichi in a time of need, but there was something familiar and comfortable about that, too.

Whatever you think you know about Kudo Shinichi, forget it. He was nothing like his popular image. The public story of Kudo Shinichi was of a teenage prodigy who had taken a short hiatus from public life in high school before reaching international stardom. He and his family cultivated an image of a fashionable, savvy detective who always fought for what's right, and they turned that mechanistically into a marketing juggernaut, selling Kudo Shinichi-branded hats, shirts, and accessories. He seemed to be the perfect man.

In reality, the Kudo-kun I knew could be remarkably petty and obsessive. If you showed up in front of him with something green stuck in your teeth, he would not rest until he found out what kind of tea you'd had, where you got it from, how much you paid for it, and whether it was any good. Nevertheless, he was one of the best private detectives in all of Japan, and one thing he that was true about his popular persona was that he would stop at nothing to save a life. Kudo-kun always said he would rather prevent a crime than solve it after the fact.

Of course, Kudo-kun was not superhuman; even he couldn't get from Tokyo to Nagano in less than ninety minutes. By the time he arrived at Amari-san's doorstep, the butter had melted, but some cake icing was the least of my concerns.

Kudo-kun arrived in a car driven by a woman I didn't know. I hadn't pegged him for an interest in older women—maybe she was around 35?—but anything was possible. Ever since the end of his engagement, Kudo-kun's intentions for dating had been mysterious to me. I thought surely he would get back together with his fiancée, but that hadn't happened yet. He must've messed up badly for her to hold out on him that long.

In spite of that, Kudo-kun seemed to be 100% focused as he stepped out of the car. He looked each way, scanning the area. "Are you all right?"

"As well as I can be after camping out on the steps to my friend's apartment for two hours," I said, getting up. "Who's your girlfriend?"

He rolled his eyes. "I haven't even been here for five seconds!" He gestured toward the lady, who locked up her car and came up the steps. "Inspector Yamato is someone I work with from time to time when I'm in the area," he explained. "I believe you two are already acquainted."

Short hair in a bun, sunglasses—it took me a minute, but I remembered that look. We'd had the fortune to meet one time in Tokyo as she and one of her colleagues had been on the way to hire "Sleeping Kogoro" for a case. I recognized the inspector, but she took off her shades and shot me a quizzical look.

"Kudo-kun and I had a small thing in common," I explained, gesturing waist-high with one hand.

She looked at him, and then at me, and she laughed. "Oh, I see! You know, Shinichi-kun is always a little vague about that. Perhaps one of you could tell me about it sometime?"

If she thought it better to know, I was prepared to explain if she and Kudo-kun could find my colleague. Only then would there be time for talking about the past. The inspector understood, and with the inspector lending her authority (along with some gloves and slippers to avoid contaminating the scene), the three of us entered the breached apartment.

Rather than turn on the lights, the inspector turned on a flashlight, and Kudo-kun did the same. I followed the two of them with just the light on my phone to guide me. In spite of the situation, the apartment still seemed tidy. There were no other obvious signs of foul play.

"Alarm deactivated when you got here, huh?" asked the inspector, who was looking over the panel. "Do you know if she sets it?"

I'd seen her set it many times. I didn't know the code, though.

"You've been here before?" asked Kudo-kun.

"I have," I said, waving my phone's light over the living room floor.

"Often?"

"Maybe ten times. She's a colleague and a friend."

"A 'colleague and a friend,' huh?" he echoed, sounding unconvinced, and on seeing the inspector was still with me, looking over the kitchen, Kudo-kun headed toward Amari-san's bedroom. Normally, I would've objected to a man entering a woman's bedroom alone, but this time, I allowed it. In fact, I couldn't help but crack a smile. From the moment he opened that door, I knew it would be less than five seconds before he realized what he'd walked into.

"M-Miyano! What is this?!" Kudo-kun's voice hit an octave I had no idea he could reach, and I followed the inspector into Amari-san's bedroom to see what the commotion was. Truth be told, I'd never been inside Amari-san's bedroom, but she'd described the contents to me several times, so I had a pretty good idea of what I would find: posters, action figures, plushies, hats, and more—all from the Kudo Shinichi collection.

"Didn't I tell you?" I said from the doorway. "She's your biggest fan in Nagano Prefecture—maybe even in all of Japan."

Kudo-kun stared, wide-eyed, at the collection of paraphernalia in horror and awe. For someone whose adult life had been spent cultivating fame and fortune, he could still be surprisingly uncomfortable with his fans. "Uh, she's not weird about this, is she?" he asked nervously.

Nothing could be further from the truth, I told him. Amari-san was a harmless fan, albeit strangely dedicated to him in ways I would never understand. She was sweet, kind, and bubbly. She couldn't hurt a fly and wouldn't dare touch him without his permission.

Kudo-kun tugged at his coat and swallowed, and he forced a smile to his lips. "Well, once we sort this out, maybe I'll sign an autograph for her."

Amari-san wouldn't be doing much with an autograph if we didn't figure out where she'd gone. Despite being broken into, the apartment was tidy—too tidy—and I couldn't think of any reason Amari-san would be harmed. She was a good student. She didn't have a boyfriend. She was doing well in her research. The only possibility that came to mind was a disgruntled competitor.

"She's perfect, then," Kudo-kun concluded with a smirk. "You're not jealous of her, are you? If you are, we'd have to consider you a suspect."

"You're not funny," I said.

"I'm hilarious," he insisted. "Yui-san, am I not hilarious?"

The inspector sighed, shaking her head, and I could see she was a kindred spirit. "I see he's like this a lot," she remarked. "I don't know whether to be relieved or frightened."

"Frightened," I said, maneuvering around her to check out Amari-san's nightstand. "Definitely frightened."

Amari-san's nightstand drawers were the first clues to what someone must've been after. They were messy and definitely rummaged through, unlike the pristine shelf of Kudo Shinichi dolls or the perfectly folded clothes in her dresser. What does one usually keep in a nightstand? Keys, sticky notes, journals, nighttime reading material? If something had been taken, it wasn't clear what. Kudo-kun agreed it was suspicious, and he decided to turn on the room lights so he could take some pictures.

"Something here!" said the inspector from the washroom.

The inspector had gone rummaging through Amari-san's medicine cabinet and found a bottle of trazodone pills alongside a booklet of past prescriptions. After taking pictures of the original configuration of the supplies, she handed Kudo-kun the bottle of pills and began to flip through the booklet, reading off a list of medications while Kudo-kun jotted them down. When the detective was through, Kudo-kun went to me, already with a theory in mind. "What is Amari-san like?" he asked.

She was enthusiastic and passionate for research. She fawned over his exploits the way someone might speak of a puppy. She was impeccably kind but stringent when it came to behaving fairly. She had some difficulty meeting new people—she could be a little shy—but on the whole, everyone in the lab liked her.

Kudo-kun and Inspector Yamato looked back at the list of medications, and they exchanged a knowing glance. "Does she sleep a lot or a little?" asked the inspector.

She was enthusiastic in attitude, but sometimes she would come in a little sleepy. She'd dismiss it as staying up late reading about her favorite detective or doing work from home. I never thought it was a problem before that moment.

That confirmed their suspicions. Kudo-kun handed over a copy of the list to the inspector, who wanted to know everything about who prescribed the medications and when. While they were busy, I took the opportunity to look something up on my phone:

Trazodone is an organic compound used as an antidepressant, said the article, as well as having secondary effects against insomnia.

I put my phone away and looked around the apartment with new eyes. With the apartment lights turned up, I saw clean carpets and walls with a smooth coat of paint. Going back into the main room, I caught a smudge on the countertop beneath the microwave. It all looked so ordinary.

I looked to Kudo-kun then, but he wasn't looking back at me. I knew right away how intensely he was thinking about this mystery. What had become of Amari-san, and who could've harmed her? His brain was already buzzing with these questions. I could see it all over his face. Though it had been years since I'd seen him regularly work cases, there are some things you just don't forget.