"You finally found out, Ran... for so many years that I've stayed in the Mouri Agency. A friend of mine from Akahibara built a time leap machine. If you wish to change the past... go there and save me!" Shinichi said. He's still in his Conan form that day and it seemed, he'll never go back to the way he is long before. 

It's already 2011 and he's still a chibi while Mitsuhiko and the others have already grown up.

Suddenly, a man wearing a white lab coat appeared before him and told him, "I won't allow it. My assistant could have built a new time leap machine which she just remembered due to a memory from the other world lines but I promised myself never to use it again. I scolded her for creating it. Today, we will disassemble it!'

"Who's he, Co---....Shinichi?" Ran asked.

Suddenly, Okabe Rintarou looked surprised and held his mobile phone and talked to it, "Is the Organization still chasing me? Wha??? They're still chasing me? Am I not in the Steins Gate World Line now? Again? Tell me, did the Organization sent a new spy? Good... good... huh... I was wrong then. Good.. I'm in my desired world line. El Psy Congroo!"

Shinichi sighed and told Ran. "Don't take him seriously. He's talking to himself yet again! He's Oka-"

Okabe Rintarou faced them and said, "I am mad scientist! Hououin Kyouma!!!" but Shinichi didn't mind him and continued saying his real name to her, "-be Rintarou. He's a self proclaimed mad scientist."

"Oh!!! Just like Professor Agasa then!!!!"

"He's much cooler though. His friends here are having a short vacation here from Akihabara.'

Soon, Okabe looked at them seriously. "How'd you know my girlfriend built a time leap machine?"

Conan smiled. "I overheard the two of you. You were talking about it."

Okabe frowned. "D-mails and the Time Leap Machine. Eventhough we know how to create one, we swore never to create it ever again! It's forbidden to be built again!"

"Ooooookaaaaariiiiiin!!!!!" was Mayuri's voice. She's with Makise Kurisu who's wearing the same type of lab coat.

Makise stared at Ran and her smile grew. She ran after her and said, "It's been so long that we haven't met!!! Where's Shinichi? Is it true that he shrank?"

Ran's eyes went sad and told her, "Yes it's true. He goes by the name Conan."

"C-Conan? Conan and Shinichi are the same person?"

'Sadly so... I'm the same person. Build me a time leap machine and I'll be the one to go back in time!" Shinichi told them but Kurisu growled like Okabe.

"Okabe protected and searched for the Steins Gate World Line and risked his life for it!!! He almost disappeared without a trace before if not for me. I have only recently brought him back from the R world line!!!" screamed Kurisu.

Then Shinichi looked away and looked at himself. "The APTX 4869 which Ai Haibara or Shiho Miyano's created isn't enough and I've grown dependent on it lessening its effect until it lost its effect on me now. The only thing I believe I can go back and return to my real self is if I go back in time and prevent myself from chasing the men in black. Oshiete kudasai!!! What will I do now? I'm stuck in being Conan!!!"

Shiho Miyano who was just there hiding behind a tree heard everything. She was back in her real body and she felt very much guilty why she didn't perfect the antidote for him. She's guilty that she had used Shinichi as a test subject. Shinichi saw her return to normal when both of them drank the antidote but he was left behind in his own state and so, that same day, she followed Okabe and his friends at the hotel they were staying at for a while.

She knocked on the door after Mayuri closed the door. "Who's that?" Daru asked.

"Who knows? Daru, you open it!" Okabe told him while he and Makise were playing a Wii Machine they just bought. They were playing a boxing game and suddenly, Makise Kurisu used that distraction to win against him who's winning repeatedly.

"Open it Daru!!!" he looked at the screen and saw that his character's knocked out by Kurisu's avatar. "Damn it!!! Who's that by the way?"

Mayuri opened the door when she noticed that the person outside the room's crying already while Daru's playing his 2d games.

Mayuri smiled at the stranger. "I heard your tears. Dry it up now. There's no reason in crying," she told her.

"Thank you... Thank you!!! You and your friends are my only hope!" she told them.

Mayuri let her inside and closed the door. Kurisu asked, "Why have you come here? Who are you? How did you know this place?"

"I followed you!!! I followed you after I overheard your conversation with Ran and Shinichi. You... you're my only hope! Please create the time leap machine!!! Shinichi's important to me!!! We're friends!! I'm Miyano Shiho and Ai Haibara!!! I used him as a test subject!!!" she cried out in guilt.

"The time leap machine can only bring memories back for only 48 hours. Also, we've already disassembled it because of Okabe's wish not to have it in this world line," Kurisu told her.

Her hopeful face went down more. "Then I have no hope."

"But we can do it with a D-mail," Daru said. 

Okabe Rintarou frowned and said, "How dare you say that to her! D-mail and Time Leap Machine can't be allowed to be made! I searched for this place and experienced too many painful ways because of doing that! I don't want to experience that again! I won't make another World Line!"

"D-mail?" Shiho asked.

"DeLorean Mail. They're mails sent to the past," Daru explained to her.

"Damn it!! Don't just say our secrets to strangers!!!" Okabe told him.

Shiho's smile came back to her but Okabe kept refusing her. "I won't or else I'll break Suzuha's wish to change the future! I promised her that I'll make the year 2036 peaceful without SERN's clutches."

"Hey. let's build it again. We haven't hacked in SERN yet," Daru said.

"NO!" yelled Okabe and Kurisu at the same time.

Shiho looked at the ground. "It's all my fault. I shouldn't have made that poison. I completed that poison..."

There, Kurisu looked at her. "What are you talking about?"

"If the two of you are scientists... I am also a scientist. I am the one who made the APTX 4869.'

"Do we make it?" asked Okabe.

"Okarin!!! She's begging for help. Why don't you just allow what she wishes you to do?" Mayuri asked.

Kurisu replied to her, "Okabe's just worried about you but I do think that because it's already new year, maybe the attractor field is different now, right? I won't die nor Mayuri will die. Let's only give her just one d-mail."

There, Shiho's eyes brightened. "Arigatou Gozaimasu demo... I'm not the one who'll send the message. It'll be Shinichi himself."

"Alright. Call him while we make the phone microwave." 

Shiho quickly called Shinichi and when her phone's connected with her phone already, she told him that Shinichi will be given a chance to send a mail that will change his past. Conan quickly told Ran that and of course, both became so happy but for Okabe and Kurisu, they're taking risks. Okabe Rintarou doesn't want to go back to the pain he had experienced long before.

Conan and Ran quickly asked her where she is and she told him that they're in Tokyo Hotel. The couple quickly went and they're finally in Tokyo Hotel, they were guided by Mayuri.

Ten minutes later, Conan and Ran entered their room with the Phone Microwave ready to be used already. There, Okabe explained what and how they would send to the past. "Sending the message to the past is risky. In our old experiments last year, I've seen how dangerous it is. One mail can change something major like Feyris sending a message to his father making the whole Akihabara lose its moe culture but in the end, I redo it and returned it to normal. Think carefully, Shinichi Kudo. When you send a message to yourself in the past, you'd lose your relationship to people who knows you right now."

"If I send my d-mail to my past self, I might never meet Genta, Ayumi and Mitsuhiko? Is that what you mean?" he asked.

Kurisu nodded and told him, "You don't need to feel down, Shinichi. If you don't have the 'Reading Steiner' an ability to remember the events from other world lines, you'd actually forget them without you noticing."

"I'll ready my text then," he said.

Kurisu and Okabe gulped. They're doing it again. Why does fate is so cruel to them, anyway?

Don't follow the men wearing black and holding a strange suitcase, it's a trap.

Conan sent the message and for months, Okabe haven't felt that familiar feeling of changing and moving into a different world line. When the force of changing world lines have ended, Kurisu looked at him. She was surprised to know that she had acquired the Reading Steiner due to time leaping into the past to help save Okabe Rintarou from forever vanishing without a trace.

"Okabe..." Kurisu held on at his arms and told him, "You've always felt this strange, strong force last year, isn't it?"

Okabe smiled at her. He's happy that finally he's not just the one who can observe the divergences and the differences of world lines which a time machne can do. When they looked around, Mayuri and Daru are staring at the two of them.

Suddenly, someone is knocking the door. "Tutturu!!! Okabe-kun, can I open the door?"

Okabe smiled and raised his head, "You can, Mayuri."

Mayuri opened the door. In an instant, someone Okabe do not know entered the door. He seemed to be a high schooler or a college student like them. His smile is so high like it could reach the heavens.

"Who are you, kid?"he asked.

"I'm no chibi!!!! Well, I just want to thank you. I finally returned to my real body permanently. Maybe, to you it's only a matter of minutes but to me, I waited for so many years just to thank you. Arigatou... Okabe-san. Kurisu-chan."

Kurisu and Okabe stared at each other and they were surprised.

"H-how?" both said in astonishment.

"There's just one explanation. He remembers being stuck as a child. He has the Reading Steiner, too!!!!" Okabe said. Then, he laughed hard, "NOW IT'S NOT JUST ME!!! FUAHAHAHAHA!!! With our abiliy, we can conquer the world!!!" He was saying that with a pose and he kept moving his hands just to hold his messy hair.

"He's speaking nonesense again," Kurisu said.

"What does he mean?"Shinichi asked.

Then, he looked around and noticed that Shiho wasn't there. "Where's Shiho? I also need to thank her for persuading you to let me send a d-mail."

Mayuri and Daru decided to leave for a while to shop while the three of them are still busy talking at each other.

"You haven't met yet, right?" Okabe asked him.

"Aa. The only hard thing having this ability is that it mixes my memories from here and from the other world line. They're both real, right?" Shinichi asked.

"Yes. They're both real but your life is totally changed due to that d-mail you sent," Okabe told him.

"Still, I want to thank you so much!!!!" after that, he left.

...

A/N: Thanks for the peron who first voted!! Arigatou!!!