Note: This version of how Doraemon ends was mainly written by Shogakukan Inc. I just added some additional details and fleshed out the storyline that they released.
"Come here, you little idiot!" shouted Gian, as he chased Nobita.
"No, I wont!" screamed Nobita, as he ran towards his house. Gian had demanded that Nobita give him the newest Slam Dunk comic that he had, but Nobita had refused.
Hence the chase.
Seeing his house round the corner, Nobita tried to run faster. But he tripped on a pebble, and, as luck would have had it, Gian caught up with him.
"I'll show you what happens to people who don't listen to me," growled Gian, as he rolled up his sleeves and advanced on the shivering Nobita.
Nobita limped into his house, after the severe trashing Gian had given him. He had lost the comic to Gian, too. As he was walking up the stairs, his mom stepped out of his room.
"Nobita! How many times have I told you to clear up your room!" scolded Mrs. Nobi, "If you don't clear up, I'll cut your allowance!"
As she stalked off towards the kitchen, Nobita entered his room glumly. As soon as he entered the room, he saw Doraemon, sitting amidst the many comic books and other things on the floor. He immediately ran up to Doraemon.
"Doraemon, give me the 'Sinking Capsules'!" he wailed, gesturing to the mess around them.
It was then that he noticed the tears in Doraemon's eyes.
"What's wrong? Are you upset with me?" he asked, moving closer to Doraemon.
"You haven't done anything to upset me… It's just… I have to go back to the future," said Doraemon, wiping his tears.
"Why? Please don't go, Doraemon!" cried Nobita, throwing his arms around Doraemon, "What would I do without you?!"
"I have no choice in this matter," said Doraemon, retrieving the Time Television from his pocket, "This is why…"
The Time Television was displaying the face of a Time Patrol officer. The officer cleared his throat, and read from a piece of paper he was holding.
"In compliance with the newly-legislated 'Maximum-Parabola' Law, created by the Time Travel Cabinet, all time travelers are hereby banned from traveling to time eras that are before their respective time eras. Time travelers are hence only allowed to travel to a maximum of 100 years in the future, from their time eras."
As the screen went black, a look of horror formed on Nobita's face, "They're banning time travel? Why?"
"Listen and you'll see," said Doraemon, pushing a button on the Time Television. The officer's image returned.
"All time travelers who are in past time eras are required by law to return to their birth eras before midnight of wherever they are. We regret if this is causing any inconvenience.
The reason for the implementation of the 'Maximum-Parabola' Law is because of the rising number of 'Time Criminals', who are contributing to a rising number of Time Paradoxes. As such, the Time Travel Cabinet is banning trips to the past.
We thank you for your co-operation."
Nobita watched as Doraemon stepped into his study desk drawer, where the Time Machine was kept. He had helped Doraemon pack his meager belongings into a bag, and was now crying as Doraemon looked at him sadly from the drawer.
"Don't cry, Nobita," said Doraemon, although he himself was crying, "It'll only be a matter of time before they revoke this terrible law."
"But how long will I have to wait for you?" asked Nobita, trying (unsuccessfully) to dry his tears.
"Just a while," said Doraemon, holding back tears, "I'll come back someday…"
The drawer closed, and the room was silent. When Nobita, done with crying, opened the drawer, it was empty. An empty wooden drawer, the Time Machine gone, Doraemon with it.
Twenty five years later……
Nobita was now married to Shizuka, his childhood sweetheart. They had had a son, Nobisuke. Nobita was the breadwinner, with Shizuka handling their house's affairs. Everything was supposed to be perfect, for Nobita had landed himself a stable, well-paying job in a shooting range as an instructor, while Shizuka proved to be a natural mother, being more than capable of caring for Nobisuke.
But their life wasn't perfect.
Their life wasn't perfect, not because of the occasional fights, or their naughty child. It was because of Nobita. He would come home from work, sit in his study, and come out only to eat or use the toilet. When Shizuka entered his study, she would find him either working or staring at an open drawer of his desk.
When she cleaned the study room, she had opened the mysterious drawer, to find it empty.
One day, when she was cleaning Nobita's study (when he was at work), she opened the drawer out of idle curiosity.
A swirling mass of blue light and distorted clocks lay inside the drawer. Shizuka finally understood why Nobita was always looking into that drawer. It had once been the entrance to the Time Travel realm, where Doraemon had docked his Time Machine. The realm where Doraemon, Nobita, Gian, Suneo, and her had traveled across time to save a dinosaur, save their past selves from Pudarandak's dog army, and what not.
So many adventures…
She then remembered the day Doraemon had left, and how Nobita had been very quiet about it…Flashback
"Hey Nobita! Let's go to the hill round back!" called Shizuka, running up to him. Nobita had seemed particularly down today, so she tried to cheer him up, "Why don't you go and call Doraemon to come with us?"
"He's gone back to the future," replied Nobita, a tiny hint of a tear appearing in the corner of his eye.
Shizuka put an arm on his shoulder, "I'm sorry about that. But he would've gone back someday, anyway…"
"I guess you're right… Sorry, I'm going home now," said Nobita, turning and walking towards his house.
The study's wooden door creaked open behind her and Nobita entered, looking sad. He saw her, standing in front of the open drawer.
"You'll wonder why I spend so much time staring into that drawer," he said quietly, crossing over to his bookshelf and lifting a heavy book from the bottom shelf, "Doraemon first appeared to me from that drawer…"
"The Time Travel Realm has re-opened, honey."
"WHAT?" With a shout, Nobita ran to the open drawer and looked into it. Sure enough, as Shizuka had said, the Time Travel Realm was accessible, the familiar looking blue light and twisted clocks making him feel pangs of sadness. They had had so many adventures in the future and past… But that was all gone now…
An idea struck him like a thunderbolt, as he realized what his options were. The Maximum thingy Law must have been revoked!
Rushing to his safe, almost knocking Shizuka down, he spun the lock, opening the safe and groping around inside.It was here! He was sure of it!
He found what he was looking for, and showed it to Shizuka, smiling.
"Remember this?" he asked her, waving it in her face.
Shizuka frowned. She had never remembered Doraemon having used a chicken-shaped alarm clock before… She shrugged, puzzled.
"This," Nobita said, shaking with excitement, "Is Doraemon's 'Long Distance Calling Clock'! It can be used to call people, wherever they are!"
"You mean…" Shizuka said, eyes wide, "That we might be able to call out to Doraemon?"
"Hopefully this thing works across time…" said Nobita, pressing the clock's alarm button. A loud, shrill rooster's crow blasted out of the alarm clock. The crowing repeated itself three times, and then the clock went silent.
Shizuka looked at Nobita, as they waited, "He left you that?"
Nobita was now staring anxiously at the open drawer, "He didn't leave me anything, actually…"Flashback
A teenage Nobita was sitting in his room, reading a comic, when two men dressed in Time Patrol uniforms materialized in front of him. He recognized the Time Travel Belts that they were wearing.
One of them spoke up, "Please surrender the back-up 4-dimensional pocket of the XD-5467 cat-type robot, alias Doraemon, that once stayed here."
"Why? He left it for me," protested Nobita, standing up. He glared at the two Time Patrol officers.
"Intervention with any previous time eras from the time traveler's time is prohibited, in compliance with the Maximum Parabola Law."
"Screw your Law!"
"We're now forced to take severe action," said one of the officers, leveling an Air Cannon at Nobita.
The officer fired, and Nobita was thrown into his bookshelf, causing an avalanche of books to cascade down upon him. A book crashed onto his head, and he lost conciousness…
Nobita remembered waking up to his mother's scolding for the mess his room was in. Apparently, the two officers had raided the room from top-to-bottom. As he cleared up, he noticed that Doraemon's 'Long Distance Calling Clock' lying in a corner. He had been using it to wake up in the morning for school, and it seemed that the Time Patrol officers had neglected to take it.
Now he could only wait. He had used the clock to call for Doraemon, across nearly two centuries of time. He prayed to whatever gods in heaven that his call would be heard…
But was interrupted in his praying by the emergence of a spherical blue head from the drawer.
As Nobita and Shizuka cried silent tears of happiness, Doraemon stepped out of the drawer.