某天，大雄如往常般，忘了做作業在學校被老師罵，也如往常般被技安、阿福他們欺負。連未來的老婆宜靜也答應要先嫁給別人。總之，對大雄來講，生活就是一連串類似事件的反覆。今天跟昨天沒什麼兩樣。唯一的變化是，小叮噹突然變成植物機器。無論大雄怎麼踢、打、罵，小叮噹都沒有反應。大雄不知道小叮噹到底發生了什麼事，只傷心得哭了整晚。可是，無論大雄再傷心透頂，小叮噹也只是紋風不動地坐在柱子前。大雄也伸手到口袋內試試，但口袋也毫無任何動靜。然後大雄想起抽屜裡的時間飛行機，就穿著睡衣飛到22世紀去找小叮噹的妹妹小叮鈴。
One day, as usual, Nobita was reprimanded by his teacher for forgetting to do the homework assignment, and as usual, he was also bullied by Takeshi and Suneo. What』s worse, his future wife, Shizuka, agreed to marry someone else. In short, for Nobita, life was nothing but the repetition of a series of similar events. Today or yesterday made no difference. The only difference was that Doraemon became a dead machine. No matter how Nobita kicked, hit, and scolded Doraemon, the latter gave out no reply. Nobita did not understand what had happened to Doraemon; he could only cry bitterly through the night. Nobita』s heart was broken to pieces. Nevertheless, Doraemon still sat motionlessly in front of the pillar. Nobita tried reaching into Doraemon』s four-dimensional pocket, but nothing happened. Finally, he thought of the Time Machine in the drawer of his desk. In his pajamas, he immediately used the time machine to fly to the twenty-second century in order to find Doraemon』s younger sister, Dorami.

小叮鈴還沒完全聽完說明，就被大雄催著坐上飛行機飛回20世紀。小叮鈴一看哥哥動也不動，馬上知道是電池用完了。正想換電池時，小叮鈴想起一個非常重大的事。沒有備用電源……大雄不懂得其中意思，只在一旁催。小叮鈴只好問大雄：你願意讓哥哥跟你的回憶都消失嗎？原來舊型的貓機器人的耳朵裡，裝有備用電源，以便充電時能保持至今為止的記憶。可是……小叮噹沒有耳朵！（這是眾所皆知的吧。）大雄終於裡解了事情的困難。種種回憶在大雄的腦海裡奔騰。大雄跟小叮噹曾飛到過去、未來，也曾到恐龍世界，海底世界，更在宇宙打仗……小叮鈴拚命解釋給大雄聽。若要裝新電池，小叮噹醒來時會失去一切與大雄曾有過的回憶。若保持現狀，記憶不會消失。結果，大雄選擇保持現狀。此時，大雄還是小學六年級。
Before Dorami could get the whole picture, Nobita rushed her to get on the time machine and fly back to the 20th century. As soon as she saw her brother』s unconscious state, Dorami knew her brother was simply out of power. But just as Dorami prepared to change the battery, she remembered one very important thing. She said to Nobita: 「there was no backup power supply for Doraemon….」 Nobita did not understand what she was talking about and kept urging her on the side. Dorami had no choice but to ask Nobita: 「Would you like all the memories between you and my brother erased?」 For old-style robotic cats usually had a backup power supply in their ears so as to retain their memories during the battery change. However, the problem was that Doraemon did not have ears! (A fact known to everyone.) Nobita finally understood what the problem was, and his brain was immediately filled with his varied memories with Doraemon: He and Doraemon had flown to the past and the future, to the world of the dinosaurs and the undersea world, and even battled in space…. Dorami explained to Nobita carefully that once she changed a new battery for Doraemon, Doraemon would wake up without any memory of Nobita. If Nobita chose to make no change, Doraemon』s memories would remain. In the end, Nobita chose to change nothing. At this time, Nobita was in sixth grade in the elementary school.

十數年後…… 從海外歸國的大雄，已成長為英俊迷人的青年，並就職於某家尖端科技的企業。他身邊的新娘，正是宜靜。當年，小叮鈴回到22世紀後，大雄只跟身邊的人們說，小叮噹回到未來的世界去了。時日一久，也就沒人再提小叮噹的事。不過，小叮噹其實一直被保管在大雄家的壁櫥裡。大雄為了修好小叮噹，拚命用功讀書，然後國中、高中、大學，成績逐年昇騰。最後出國到著名的大學留學。現在，大雄身在他自己的研究室中。他叫來平日嚴禁其出入研究室的妻子宜靜。對她說：妳看好，我要按開關了。說完，大雄頰上情不自禁流下兩串淚珠。就是為了這一刻，苦學了十幾年……為了這一刻，從一個老是忘了做作業、成績從倒數起算比較快的笨學生，爬到今天的地位……開關按下後，久久一陣靜寂，靜寂……終於，小叮噹開口了：『大雄，我等你很久了。』
After more than ten years, Nobita had grown up into a handsome and charming young man. He had come back from studying overseas, and is now working in one high-tech company. The bride next to him is exactly Shizuka. After Dorami returned to the twenty-second century, Nobita only told people around him that Doraemon had already gone back to the twenty-second century. As time flew, no one ever mentioned Doraemon any longer. However, the truth was Doraemon had been stored in Nobita』s closet all this time. In order to repair Doraemon, Nobita kept studying hard and made great progress through junior high, senior high, university, and eventually going abroad for advanced studies in a well-known university. Now, Nobita has his own laboratory. He usually forbade his wife to enter the laboratory, but today, he summoned Shizuka to enter the room and told her: 「Look closely. I am going to switch the power on.」 Nobita could not help crying. He had studied all these years for this moment….For this moment, he had changed from a stupid student who always forgot to write his assignment and got very bad grades in his class into the position he has today….After switching the power on and waiting through a very long silence, Doraemon finally opened his mouth: 「Nobita, I have waited for you for a long time.」