Hayashi Yoshiki took Haibara Ai to an apartment. When he rang the doorbell, the person who quickly came to answer was Narumi Asai.
"Mr. Hayashi, Ai-chan," he greeted, stepping aside.
"Excuse me. How is the child?"
"There's nothing wrong with him," Narumi Asai said with a wry smile.
"But he has trouble trusting me."
Hearing this, Haibara Ai became slightly curious. But as she stepped inside, she soon saw a strange little boy—about four or five years old—staring at them, bewildered.
The moment the boy recognized Hayashi Yoshiki, his expression shifted.
"It's nice to meet you again, Hiroki."
"Yoshiki…," Hiroki Sawada murmured, almost calling him nii-san, but the word wouldn't come out.
It was all too surreal.
After being taken by the Black Organization to a strange factory, Hiroki had met the boss of the assassins—a short, fat middle-aged man who had handed him a mysterious pill, saying it would bring a painless death.
To Hiroki, who had resolved to die at the time, this was tempting. He knew that neither he nor Noah's Ark could fall into the hands of any organization. So, despite not knowing why they wanted him dead, he swallowed the pill.
But the drug's effect nearly tore his body apart. After losing consciousness from the pain, he woke up to find himself… smaller. A seemingly kind woman named Narumi Asai had taken him in—but Hiroki, scared by betrayal, remained suspicious.
He believed this must be another organization seeking Noah's Ark or his programming skills. Then Hayashi Yoshiki appeared—revealing his identity after Hiroki had shrunk. Which meant…
He was one of them.
A chill crept down Hiroki's spine.
Sometimes, when someone sees a sliver of light in the depths of despair, they cling to it. They beautify that memory, and turn it into something sacred.
But now, Hiroki feared he had been deceived. In his mind, Hayashi Yoshiki began to resemble Moriarty from "Cocoon."
"I'm sorry for hiding so much from you," Yoshiki said gently, noticing Hiroki's tense, helpless look.
"But don't be afraid. You've escaped that organization now. I understand your caution—but I have no interest in Noah's Ark. In fact, I agree with your decision to destroy it. Until the right time comes, it's as dangerous as Pandora's Box."
"Noah's Ark? Hiroki?"
Haibara Ai froze in shock, staring at Hayashi Yoshiki. "He took APTX4869?!"
"Yes," Yoshiki said gravely. "It was the only way."
"APTX? What's that?" Hiroki asked.
"That drug you took," Haibara said flatly. "It's an experimental compound—usually lethal. It kills quickly, leaving no trace. But there are rare exceptions like you… where it triggers a 'reverse aging' effect."
The puzzle pieces clicked together in Haibara's mind.
She turned to Yoshiki, her expression dark.
"So he was the one the Organization was after that night?"
"That's right."
"…An artificial intelligence creator. Of course, they'd lose their minds over someone like him."
She stared at Yoshiki in disbelief, fear rising in her chest.
"And you told me you weren't involved in what happened that night!"
"I didn't act impulsively," Yoshiki replied. "But I had no other choice."
"What do you mean?"
"Whether it was about saving the child… or protecting you. You do realize, right? If they got Hiroki, they'd use Noah's Ark to find you!"
Yoshiki's calm demeanor finally cracked—his voice stern, intense.
Haibara Ai couldn't respond.
She pressed her lips together tightly. She hated how she kept bringing trouble to him—hated how he always sacrificed for her.
Why me? Why does he always do this for me?
"…So what exactly is going on?"
Hiroki, still wary, listened and slowly began to understand. Perhaps they weren't with the Organization after all…
Seeing the boy's distrust, Haibara frowned.
"Do you know what kind of risk he took to rescue you?"
"Easy, Ai" Yoshiki said gently, patting her on the back.
Then he addressed Hiroki directly.
"The Black Organization is a covert, multinational crime syndicate. Its key members go by the names of alcoholic drinks. I imagine Noah's Ark helped you discover some of this?"
"…Yes," Hiroki replied.
"Then let me formally introduce myself. My code name is Cointreau. Her former code name was Sherry, though she's since defected."
Yoshiki explained everything—how APTX4869 was developed by Haibara Ai's parents, how she escaped the Organization, and how they both sought to protect Hiroki.
The boy listened in silence.
He was just ten years old.
"…But you didn't have to save me," Hiroki said eventually. "I would've disappeared along with Noah's Ark. That would've been the best ending."
His voice was quiet and bitter, though tinged with a faint smile.
"At least… I played a very fun game before the end. I was happy."
Smack.
A book landed softly on Hiroki's head.
Dr. Narumi Asai, who had been silent, couldn't take it anymore. He tapped the boy lightly with a medical textbook.
"Life isn't something you can throw away so easily," he scolded. "Especially not when someone else risked everything to save you. You owe it to him to live."
"I…"
"I just took a gamble," Yoshiki said calmly. "The odds of surviving APTX4869 are extremely low. But I couldn't just let you—someone who's never known freedom, never had friends—die alone in the dark."
"…Luckily, it worked."
"So forget everything. Forget the Organization, forget Noah's Ark. From this moment on, live as a normal child."
"You'll make friends. You'll play. Computers and programming can wait until you're older."
Hayashi Yoshiki smiled gently, bathed in golden afternoon sunlight.
It was a warm, reassuring smile. And for the first time, Hiroki's vision blurred with tears.
"…Onii-san, I—"
"It's okay. I have to go. You prepare to enjoy your new life."
Hayashi ruffled Haibara's hair, indicating it was time to leave.
"Leaving already?" Narumi blinked. "I haven't even served tea."
"I have an appointment. As for the boy, I'll leave him in your care, Dr. Narumi"
"Of course. It'll be nice having a kid around."
As Narumi went to see them out, Haibara said suddenly, "Can I come back later to draw some blood? A ten-year-old turning into a five-year-old… he and I don't quite match biologically. It's worth examining."
"…That's…" Yoshiki hesitated.
"I don't mind," Hiroki cut in.
Yoshiki smiled and walked out with Ai.
Once in the car, Ai turned to him. "Do you really have an appointment?"
"Nope."
"Then why?"
"…I just didn't like the atmosphere in there," Yoshiki said, starting the engine. "Besides, Hiroki will be safe now. Someone like me, who's still connected to the Organization, shouldn't stay near him. I'd only endanger him."
Vroom.
The car pulled out of the lot.
Haibara stared at him, then looked away toward the window.
"…Stupid nice guy."
She sounded irritated.
It was always the same. He'd give his all, never asking for anything. Then brush it off with some excuse—"I don't like that kind of atmosphere."
He did it for her, for Hiroki, even for that girl Ran…
Always protecting others, never once caring for himself.
"Cointreau."
"Hmm?"
"Don't get yourself killed."
"I won't."
"I mean it. If anything happens to you… I'll never forgive you!"
Her serious expression was tinged with a kind of quiet fire. She looked fierce—and maybe even a little cute.
Yoshiki smiled. "I promise."
As she turned her head again, he felt oddly content.
Hiroki was safe.
Yoshiki couldn't be certain if Noah's Ark had truly destroyed itself—but as long as Hiroki lived, that didn't matter.
And Hiroki Sawada was not the type of child to forget someone who'd shown him warmth.
Especially a boy like him—so emotional, so sensitive.
In time, Hiroki would seek him out again. And when he did, perhaps he could help Hayashi Yoshiki hide in the shadows of the Organization… and eventually destroy it.
Back at the apartment, Narumi turned to Hiroki with a smile.
"All right. I'm Narumi Asai. From now on, I'll be teaching you."
"…Nice to meet you, Onee-san."
"Well, I'm actually a guy."
"…Huh?"
"I said I'm a man," Narumi said, chuckling as he poured water.
Sitting on the couch, Hiroki took a while to process this. Still holding the cup, his eyes were filled with confusion about the future.
"Don't overthink it. Just do your best not to disappoint Mr. Hayashi. Try to live like a normal child."
"…I will. But Narumi… can you tell me more about Yoshiki?"
"Of course."
Masashi smiled, sitting back and looking at the ceiling.
"Actually, I'm just like you. Mr. Hayashi saved my life, too."
"…Really?"
"Yes. He was a brilliant detective. And I was a small-town doctor—just one step away from becoming a murderer. Many years ago, my father…"
And thus, he began to tell the story of how his life was saved by Hayashi Yoshiki.