Summary: Kouichi lost his memory after he witnessed something he wasn't supposed to see: a murder. Despite suffering from amnesia, the murderer isn't willing to let his only witness go free, even if he is just a child. Can Kouji and his friends protect Kouichi from a heartless killer? And how can Kouji help his twin regain his lost memories when they're too painful to remember?

Crossover fanfic with characters from Digimon Frontier and Detective Conan. I owe neither so this is my disclaimer.

Prologue

BEEP. BEEP. BEEP.

Kouji stirred, cracked open an eye, and glared at the heart monitor. Naturally, he didn't want it to stop, but the loud, incessant noise started to irritate him. Tiredly, he sat up straight and rubbed the sleep from his eyes. He glanced around the room and saw that he was the only visitor here. Voices were exchanged from beyond the closed doors in the hallway. Other than that, it was just him.

Well, he and the patient.

Kouji turned to glance at the prone figure lying on the hospital bed in front of him. With a heavy and tired sigh, he leaned over to fold his arms, resting on the patient's stomach. He rose and fell with each of his brother's soft breathing. Kimura Kouichi, his twin, looked so small and frail as he lay there before him, especially with the oxygen mask over his nose and mouth. Needles and other implements hooked him to an IV drip bag, a heart monitor, blood pressure monitor, and other various forms of life-supporting system. There were thick bandages wrapped around Kouichi's forehead, as well as the upper left side of his chest n the axilla area close to his clavicle collar bone. Kouji could see the whites of those bandages just barely out of view from beneath his brother's hospital gown.

Kouji reached out to take his brother's hand in his, feeling his twin's steady breathing. All the while, he could still hear the loud beeping of the heart monitor next to him.

BEEP. BEEP. BEEP.

Kouji gave another tired sigh and reached out a hand to brush a strand of hair from his brother's closed eyes. How could it be so loud in here and yet still so silent?

"Kouichi-niisan…" Kouji said softly. "Nii-san, c'mon. It's been three days. Please…open your eyes. I…I miss you…" His voice faltered. Still, Kouichi didn't stir. He took his brother's hand in his again and tightened it ever so slightly. "I miss your laughter. I miss hearing your voice. And worse of all, I miss your smile."

Kouji paused, feeling tears threatening to well up in his dark, blue eyes. Furiously, he rubbed them away on his sleeves. The last thing he wanted was to show his vulnerability should a nurse or a doctor come in.

He turned to his brother, hoping against all hope that his prayer would be answered. Let Kouichi hear him and find his way back to him, his heart silently prayed.

But Kouichi remained unresponsive.

Disappointed, Kouji leaned back against his chair and closed his eyes to think.

How could this have happened? Kouji thought miserably. The two of us should be getting ready for the summer festival in Izu with the others. We should be celebrating and having fun! Instead…

His mind trailed off to that horrible night when it all happened. They had been attending one of their father's boring business parties. Kouji silently cursed himself for not putting up more of a fight when he remembered that event. He should have pressed harder—argued—screamed—anything to remind his father that he and Kouichi didn't want to come along and play the dutiful sons. But his father had pulled a nasty trick out of his sleeves, offering the twins a deal they desperately wanted as a reward, but only if they could just put up one evening in a set of fancy-dress suits for his sake. And so, Kouichi and Kouji were forced to accompany their parents at this stupid gathering! There had been other younger attendees around their age, and meeting one or two of them had been interesting enough, but after nearly five hours, things went wrong. Seriously wrong.

Seeing how tired her stepsons were, Satomi suggested that she drive them home to get ready for their trip early the next day. Hearing this, Kouichi had offered to retrieve the keys and their coats from the cloakroom downstairs.

The bitter memory caused Kouji to clench his teeth. That had been the last time he saw his brother smiling before he walked off. The next thing they knew, there had been a blackout throughout the entire building. When Kouichi didn't come back several minutes after the lights came back on, Kouji knew something was wrong. He felt it in his gut, making his mind uneasy. Dread and fear took hold of his heart. Kouji felt it within himself like a persistent calling, and it drew him out of the ballroom in search of his twin. It felt like a deep, heavy, and sickening sensation in the pit of his stomach. It pulled and tugged until—

To Kouji's horror, he found his twin lying unconscious and bleeding to death at the bottom of the stairs down the hallway. The culprit who had shot him and killed another was nowhere to be found.

What followed was chaos and panic. One of Kousei's business clients had been found murdered in his hotel suite upstairs. The police arrived swiftly and were hounding everyone with questions. Kouichi was immediately rushed to the nearest hospital and straight into surgery. After a long and agonizing wait, the doctors and nurses finally emerged from the operating room. They assured the family that Kouichi was alive, but he remained unresponsive. Due to his head trauma, he was rendered unconscious for an undefined time.

A coma, one of the doctors had told his parents. It was hard to tell how long it would last at this point. A few days? Perhaps a few weeks? Or months? They just weren't sure, but all Kouji knew was how torturous the wait was going to be for him.

Three days. It had been three days since that horrible night, and still, his twin brother hadn't stirred. Hasn't even fluttered an eye open. Not so much as a twitch of a finger.

Kouji didn't know how much more of this he could take. He was starting to feel numb. He feared that by the time Kouichi wakes—if he wakes—there would be nothing left of him to feel.

Kouji rubbed his eyes and got up to stretch. When he was finished, he got up to change the water in the flower vase sitting on a bedside table next to his brother's bed. They consisted of lavenders and lilies in various shades of white and purple. They were Kouichi's favorites.

A sudden knock brought his attention to the doors. A boy with messy brown hair stepped in. he was sporting a red t-shirt with an orange and yellow fireball logo and shorts. The entire outfit was offset by a large pair of square-shaped goggles strapped over his burgundy baseball cap. Kanbara Takuya quietly closed the doors behind him and gave his best friend an encouraging smile.

"Hey, buddy. How's he doing?" Takuya asked. Kouji sighed and shook his head. "Still nothing?"

"No," Kouji replied with a deflated tone.

Takuya shook his head sadly and took the empty seat next to Kouji's. "Hey, cheer up. It will be okay. Kouichi will come back to us." He trailed off, glancing over at his unconscious friend. "He has to…" he added softly under his breath.

Kouji sank back down onto his chair. "Easy for you to say, goggle-head," he huffed, crossing his arms. "You weren't there. You didn't see Kouichi lying on the ground in a pool of blood."

"No, I didn't…" Takuya said. He tried to ignore the bitterness in his friend's tone. He could hardly blame him for feeling this way.

A moment of silence passed between them.

"Any updates on the investigation?" Kouji asked, not bothering to glance at him.

Takuya shook his head. "No, nothing yet, I'm afraid," he said. Remembering something, he raised his eyebrows. "But my dad said he and Inspector Megure are still working hard on it. I heard they're bringing in that high school detective to take a look at the case."

Kouji scoffed and rolled his eyes. "I doubt he'll be of much help."

"Don't be so sure on that! My dad said this high schooler, I think his name is Kudo Shinichi or something, hasn't failed to solve a case yet!"

"The keyword to that sentence is yet, Takuya."

Always the nitpicker, Takuya thought.

"Yeah, well, they say he's like a child prodigy when it comes to forensic detective work or something. Haven't you seen him in the news and the media? He's really good!"

Kouji turned and gave Takuya a derisive look. "If he's so good, then why hasn't he caught the bastard that did this to my brother?!"

Takuya's grin disappeared. "Hey, chill, man! They just called him in! I'm sure this Kudo kid will be able to help somehow. He's got to…or else the culprit who did this to our friend is still…" He paused, not wanting to finish that sentence.

Kouji said nothing. They both didn't want to say it. Instead, he continued to cross his arms as he sank further into his seat. Takuya sighed. Honestly, he hadn't seen his best friend so lost and sullen since meeting Kouichi for the first time and finding out that they're brothers.

"Don't worry; it just takes time. We all have to be patient," Takuya said.

Again, Kouji said nothing. He didn't even bother to point out that Takuya isn't the most patient in the group. Together they sat in silence, staring at the empty wall opposite them and occasionally glancing at Kouichi.

Takuya never really liked being quiet. Silence makes him feel awkward. He was active and social, and the sour mood started to get to him. He snuck a glance at Kouji. After a while, he asked, "What about you? How are you holding up?"

Kouji shrugged.

Takuya frowned, but he knew he had to keep trying. "C'mon, buddy! Have you seen yourself? There's a mirror on the bedstand! I don't mean to sound rude, but—"

"So, don't."

"—Kouji, you look like crap! Did you get any sleep these past few days?"

Kouji lowered his head and sighed. "Barely," he replied exasperatedly. He turned and pinned Takuya with a glare. "What did you expect? How can I sleep knowing that Kouichi's been hurt?" He turned away.

That was half true. Kouji didn't want to tell Takuya that the nightmares would come every time he closed his eyes. In his dreams, he saw his brother running down that same dark hallway, desperately trying to get away from a shadowy assailant. As soon as he reached the stairs, the dark figure pulled out his gun and fired at the boy. Kouichi gasped in shock as the bullet flew through his left axilla area, sending him tumbling down the stairs. The back of his head smashed against the ground before he could register the pain. As darkness took him, Kouichi whispered his brother's name, desperately calling out for help. Kouji tried to reach out for him, but the nightmare shattered and ripped into pieces every time he did. Nothing saved for a peal of soft and dark laughter that sent chills down his spine. Kouji would wake up in the middle of the night, gasping for breath and covered in sweats.

No, Kouji didn't want to tell anyone of his reoccurring nightmares, not even to his best friend.

I should have been there! Kouji thought miserably. I should have gone with him! It's my fault that he's hurt!

Takuya studied his friend and frowned. He may not be the most observant and intuitive of the group, but even he could tell how troubled Kouji was. And was sort of friend he would be if he didn't try and help?

"Hey, c'mon, buddy," Takuya said, slapping a hand on Kouji's shoulder. "You gotta pull yourself together! Kouichi is going to be alright! Trust me. He is much stronger than you or even our parents realized. I mean, c'mon! He's a Legendary Warrior, for heaven's sake! He took out that creep IceDevimon and saved both our asses from being frozen popsicles! After all the battles and turmoil we had been through in the Digital World last year, you out to know that Kouichi is made of harder stuff! Like a diamond, you know?"

Kouji lifted his head and scrutinized him, raising an eyebrow in perplexity. "A diamond, huh?"

Takuya grinned. That stupid, cheeky, Takuya-esque grin. Rubbing the back of his head, he laughed. "Okay, I'll admit that was cheesy, and to be honest, I kinda borrowed that line from Izumi-chan. You know how much she's into this girly, poetry stuff. But then she does have a point, you know? Kouichi is kind of like a diamond, right? When we first met, it was rough because Cherubimon brainwashed him. But he shined through after meeting you and fighting alongside us against the Royal Knights. I mean…" Takuya trailed off for a moment. "He sacrificed himself so that we could have the power to defeat Lucemon. And that, my friend, must have taken a lot of courage."

Kouji blinked and nodded all the same. "Yeah, I supposed you're right." Who knew Takuya had such a perspective as deep as that? He glanced at his brother again and smiled sadly. "I can't believe it's been a year since we first met. I'd never imagined having a brother after so long. I thought I was an only child because my dad lied to me for ten years. But still, a part of me felt something had been missing." He turned and looked at Takuya. "Having you guys in my life as friends is great, but—"

"But with Kouichi with us, it's better, right?" Takuya grinned.

"Yeah." Kouji tilted his head up towards the ceiling. "It was thanks to Kouichi that I found out that my biological mother is still alive. When he told me how much her stress was exacerbating her health, mentally and physically, I felt so useless." He paused, and his expression turned thoughtful. "Meeting my mom after all these years helped her. With Kouichi and me in her life, she got so much better. That's more than I could have asked for. In a way, Kouichi is the light of my life," Kouji leaned forward in his chair. "Even though my dad and I still don't see things eye-to-eye, Nii-san's always been there to make it better between us."

Takuya nodded. "I guess Kouichi's always been the calm and soothing presence we didn't realize we needed," Takuya said.

"Just like the true nature of darkness; his element," Kouji nodded. "We haven't been together long, but I can't imagine my life without him now."

"Neither can I nor the others," Takuya smiled. "Your brother may not have been a part of our group for as long as the five of us, but he's still one of us regardless. Kouichi's our friend, and he has been there for us! So when he wakes up, you and I and the others will be here to help him in return. We stick together, all six of us, so don't you worry about it. He'll come back to us just like the last time." He paused to lower his head. "He'll come back…I just know it. And you have to believe it, too, Kouji."

"Yeah, you're right," Kouji said and smiled a little. "Thanks, Takuya."

Takuya gave him a stupid grin. "C'mon, what's a little heart-to-heart pep talk between friends, am I right?"

"Don't get too sentimental. It's really not you."

"And there goes the shortest gratitude from a friend I'll ever get!" Takuya laughed. "But don't worry, 'cause I forgive you. You're welcome, by the way! After all, what are friends for?"

Takuya clapped a hand on Kouji's back heartily. Kouji pinned him with a look. He usually doesn't like strangers touching him. Even amongst friends, he tried to tolerate it to an extent. His family members, especially his brother, tried to keep it personal and private. For now, he'll let Takuya get away with a warning.

Kouji turned to his friend and was about to open his mouth and tell him to take his hand off his back when he heard something soft, like a mumbling.

"Did you say something?" Kouji asked.

Takuya blinked, then shook his head. "No, why?"

They both exchanged confused looks before turning their heads.

Kouichi moaned and stirred ever so slightly. The two friends' eyebrows rose in surprising unison. For a moment, Kouji held his breath. He got to his feet and was immediately by his brother's side, leaning in to caress Kouichi's face.

"Nii-san?" Kouichi asked, his voice soft and full of hope. "Nii-san, can you hear me?"

As if the sound of Kouji's voice coaxed him, Kouichi's eyes opened very slowly. Kouji gasped and couldn't help but smile. At last! His twin was waking up! It may have been only three days, but it felt like an eternity to him.

Blinking away the drowsiness he was still feeling within himself, Kouichi first glanced around before realizing someone was right next to him and was staring at him excitedly. Kouichi tried to tilt his head.

"Nii-san?" Kouji whispered.

"Mmm…?" he mumbled softly.

For a moment, the two brothers just looked at each other; two pairs of blue eyes met as if for the first time in years. Kouichi blinked a few more times, his expression numbed, tired, and confused—all of which Kouji brushed off.

"Nii-san! Thank goodness!" Kouji cried and wrapped his arms around his brother, burying Kouichi's face in his chest. "You're awake! You're finally awake!"

The excitement was contagious as Takuya couldn't help but smile. "Welcome back, Kouichi! You really gave us quite a scare, you know?"

"Hmmph…mmm…hmmph!" Kouichi mumbled.

Takuya laughed. "Kouji, I think you might want to give him some air."

Kouji ignored him. He was so happy to have his brother back that he tightened his hug around his brother. But then, he felt something off. Much to his surprise, Kouichi was struggling in his grip. He moved his head back and forth, and his breathing turned into panting as if he was out of breath, struggling to escape. Quickly, Kouji loosened his embrace.

"Sorry about that, Nii-san," he apologized. Giving his brother some space, he leaned back to take in his brother's state fully. "How are you feeling?" he asked.

Kouichi was still panting as if he had woken from a bad dream. To Kouji's surprise, he continued to give him that strange look. It was blank and a confused one. For a moment, Kouji thought he saw a glint of fear in those gentle, dark, blue eyes that were so much like his own.

Kouji leaned in, gently caressing his brother's face. Kouichi winced and jerked back from his touch. Alarmed, he said, "Nii-san, what's wrong?"

Kouichi stared at him and glanced around nervously, uncertain of where he was. His eyes slowly traced from him to Takuya and then back to him again. Opening his mouth, his brother spoke in a dry, raspy voice.

"Who…who are you?"

Author's note: Wow, I haven't written a Digimon Frontier fan fiction in a while! This idea has been on my mind recently, and I was inspired after I re-watched the 4th Detective Conan movie, Capture in Her Eyes. The plot will be different though, and while this is technically a crossover, it will mostly focus on the characters from Digimon Frontier, especially the twins. Some characters from Detective Conan will make a cameo, while others will play a more prominent role to help the story.