After everyone went to bed, Shin quietly sat in his room. He pulled out his bag and took out the Kiteretsu Daihyakka. The old book felt heavy in his hands. Next to it were the special glasses that Kiteretsu used in the anime.
Shin put on the glasses. Immediately, the words in the encyclopedia became clear and easy to read. Without the glasses, the book looked completely empty. But with them, everything made sense.
"Now, let me find it," Shin whispered to himself.
He started turning the pages carefully. There were so many inventions - flying machines, robots, time devices, and more. Each page had detailed drawings and instructions. Finally, after searching for several minutes, Shin found what he was looking for.
"The Turtle Submarine!" Shin said excitedly.
The page showed a submarine shaped like a turtle. The instructions explained how it worked. It used oxygen as fuel, and there was a special liquid that could separate oxygen from water. That meant the submarine could run forever as long as it was in water and had some of that special liquid. Just one small bottle could power it for days.
Shin read everything carefully. But then he realized a big problem.
"I need materials to build this," Shin thought. "Metal, tools, wires, everything. And I need space to work. My room is too small."
He looked around his small room. There was barely enough space to walk around. How could he build a submarine here? And where would he get all the materials?
Shin sat there, thinking hard. Then an idea came to him. The answer was just across the hall. Doraemon! Doraemon had gadgets for everything. Maybe he had gadgets that could help.
"I need to ask Doraemon for help," Shin decided.
He stood up and walked to his door. He opened it slowly and quietly. The hallway was dark. He could see light coming from under Nobita's door. They were still awake.
Shin walked toward Nobita's room. When he got close to the door, he heard voices inside.
"Please, Doraemon! Please!" That was Nobita's voice, and he sounded like he was begging.
"I don't know, Nobita. Do you really want to go on a yacht trip that badly?" Doraemon's voice replied.
"Yes! Suneo was bragging so much! I want to go on a yacht trip too! Please help me!" Nobita pleaded.
Shin smiled. Perfect timing! Nobita was asking for the yacht trip, just like in the anime. This was Shin's chance. He could offer to help them with his submarine.
Shin knocked on the door and opened it. The sight inside was funny. Doraemon was sitting on the floor, looking like he was thinking about something important. Nobita was sprawled on the floor in front of him, literally begging like a puppy.
"Shin!" Nobita said, looking embarrassed. He quickly tried to sit up properly, but he was too slow.
"Doraemon, can you come with me for a moment? I need your help," Shin said before Nobita could say anything.
"Me? You need my help?" Doraemon looked confused but interested. "Sure, I'll come."
Doraemon stood up and followed Shin out of the room. Nobita stayed behind, still looking embarrassed.
In Shin's room, Doraemon sat down on the floor. Shin sat in front of him, looking serious.
"What do you need help with, Shin?" Doraemon asked.
"I heard Nobita asking you about a yacht trip," Shin said. "I know he wants to go on one because Suneo was bragging."
"Oh, you heard that?" Doraemon looked a bit embarrassed. "Well, yes. Nobita really wants to go."
"I have a way to make that happen," Shin said confidently.
"You do? How?" Doraemon leaned forward.
"I can't tell you exactly how yet. It's a surprise," Shin smiled. "But I need your help with something. I need three things."
"What three things?" Doraemon asked.
"First, I need a gadget that can give me a lot of space to work in. Like a big room. Second, I need a gadget that can give me materials to build things. And third, I need a gadget that can give me more time to work," Shin explained.
Doraemon scratched his head. "That's interesting. I don't really understand what you're planning, but okay. I'll help you!"
"Really? Thank you so much!" Shin said happily.
Doraemon reached into his four-dimensional pocket. "Let's see. For space, I have this!"
He pulled out something that looked like a poster, but it was shaped like a door. The poster was rolled up. Doraemon walked to a wall in Shin's room and stuck the poster on it. Then he unrolled it. On the poster was a picture of a door.
"This is the Spare Room Door!" Doraemon explained. "Watch this!"
Doraemon grabbed the doorknob on the poster and pulled. To Shin's amazement, the poster opened like a real door! Inside was a massive empty room. It was huge - maybe ten times bigger than Shin's current room. The walls were white, and there were bright lights on the ceiling.
"Wow! This is perfect!" Shin said, looking inside with wide eyes.
"I'm glad you like it!" Doraemon smiled. "Now, for materials..."
Doraemon reached into his pocket again and pulled out a pink handbag. It was small and cute-looking.
"This is the Obtaining Bag," Doraemon said. "You can reach inside and take out any material you want. Just think about what you need, and it will appear!"
"That's amazing!" Shin took the bag carefully. "This is exactly what I needed!"
"And for time..." Doraemon pulled out one more thing. It was a sticker that looked like a clock. "This is the Three Times Speed Sticker. If you put this on yourself, your speed will increase three times. That means you can work for three days while only one day passes for everyone else!"
Shin took the sticker. "Thank you so much, Doraemon! These are perfect!"
"You're welcome," Doraemon said. Then he looked curious. "But Shin, what are you going to do with all this?"
"It's a surprise," Shin smiled mysteriously. "But I promise, you'll love it. Trust me."
Doraemon looked at Shin for a moment. Then he smiled. "Okay, I trust you. You seem like a smart boy."
"Thank you for trusting me," Shin said.
Doraemon stood up. "Well, I should go back to sleep now. Good night, Shin!"
"Good night, Doraemon!"
After Doraemon left, Shin looked at the three gadgets. The door to the huge room. The pink bag for materials. The speed sticker for time. Everything he needed was right here.
"Time to get to work," Shin said to himself.
He put the speed sticker on his shirt. Immediately, he felt different. Everything around him seemed to move slower. Or rather, he was moving faster. This was perfect.
Shin picked up the Kiteretsu Daihyakka and walked through the poster door into the huge empty room. He looked around, admiring everything. The room was completely empty, but it had good lighting and lots of space. Perfect for building.
Shin sat down on the floor with the encyclopedia. He put on the special glasses and started reading the instructions for the turtle submarine again. He read every detail carefully.
"The submarine works on oxygen as fuel," Shin read aloud. "It uses a special liquid to separate oxygen from water. So it has unlimited power as long as it's in water and has that liquid. One small bottle of liquid can run for days."
Shin started planning. First, he took out a pen and paper from the Obtaining Bag and started sketching.
The original turtle submarine design was okay, but Shin wanted something better. Something cooler. He was going to build his own version.
"The original design looks too much like a turtle," Shin thought. "I want something that looks more modern. Like a spaceship mixed with a boat."
He started drawing. Lines appeared on the paper. Curves and angles. Slowly, a design took shape. The submarine looked sleek and futuristic. It had smooth curves like a spaceship, but the shape was perfect for moving through water like a boat. Anyone who loved machines would drool looking at this design.
"Perfect!" Shin said, looking at his sketch.
Now for the size. Shin decided to make it small at first - just big enough to reach his chest. Later, he would use Doraemon's Big Light gadget to make it bigger. That way, it would be easier to build and transport.
Shin reached into the Obtaining Bag. "I need metal sheets," he said.
His hand touched something cold and smooth. He pulled out a large sheet of metal. It was perfect!
He kept taking out materials - tools, wires, screws, bolts, everything he needed. The Obtaining Bag really was magical.
Shin started working. First, he created the outer shell of the submarine. He cut the metal sheets carefully and bent them into the right shapes. He welded the pieces together. His hands moved fast because of the speed sticker. What would normally take hours only took minutes.
Next, he built the power system. This was the most important part. He created a special chamber that would hold the oxygen-separating liquid. He connected it to an engine he designed. The engine would use oxygen from the water to power the submarine.
Then he built the interior. Seats to sit in. A control panel with buttons and screens. Windows to see outside. He even added a small restroom, something the original turtle submarine didn't have.
"If we're going to spend a few days in the ocean, we need a bathroom," Shin thought practically.
But then another idea came to him. They would need beds too. And a kitchen for food.
"I know!" Shin said excitedly. "I'll create a separate extension!"
He started building a second part - an extension that could attach and detach from the main submarine. This extension would have bedrooms with comfortable beds, a full bathroom with a shower, and even a kitchen and dining area.
The extension was designed to mechanically latch onto the main submarine when they needed it. When they didn't need it, they could detach it, shrink it with the Small Light gadget, and carry it around easily.
Shin worked through the entire night. His hands moved quickly, building and creating. The submarine slowly took shape.
By morning, he stopped to take a break. He left the room and had breakfast with Nobita's family. Then he went back to work.
All through the next day, Shin worked. He ate lunch with the family, acted normal, and then returned to building. Nobody suspected what he was doing in his room.
Shin even slept for a few hours. But because of the speed sticker, sleeping for two hours felt like sleeping for six hours. He woke up refreshed and continued working.
Finally, on the evening of the second day, after dinner, Shin called Nobita and Doraemon to his room.
"Tomorrow, be ready for an ocean trip," Shin announced.
"Ocean trip? Really?" Nobita's eyes lit up.
"Yes. And call Shizuka and Gian too. Tell them to come early in the morning," Shin said.
"But how are we going to have an ocean trip?" Doraemon asked, looking confused.
"You'll see tomorrow. Just trust me," Shin smiled. "And Doraemon, I might need to borrow your Big Light and Small Light gadgets tomorrow."
"Sure, but I'm really curious about what you're planning," Doraemon said.
"If Shin's plan doesn't work, I have my own gadgets ready," Doraemon thought to himself.
"Don't worry. Everything will be perfect," Shin assured them.
After they left, Shin went back to the spare room. He looked at his creation. The submarine was almost complete. Just a few more touches.
He created gallons and gallons of the special liquid needed to separate oxygen from water. He filled several containers with it and stored them inside the submarine.
Finally, he decided on the color.
"Red looks cool," Shin said. He took out red paint from the Obtaining Bag and carefully painted the entire submarine. The red color made it look even more amazing and futuristic.
By late night, everything was finished. Shin stood back and looked at his creation. The sleek red submarine gleamed under the lights. The detachable extension was ready beside it. All the liquid containers were prepared.
"I actually did it," Shin whispered in amazement. "I built a submarine using the Kiteretsu Daihyakka!"
He felt proud. In his previous life, he had been just a normal teenager who watched anime. Now, he had built something incredible with his own hands.
Shin took off the speed sticker and walked back to his regular room. He lay down on his futon, exhausted but happy.
Outside, the night was quiet. Tokyo was sleeping. But in Shin's spare room, a red submarine waited, ready to dive into the ocean and explore the underwater world.