Glad that Kah Shoon sent me this mail, if not i will never be able to know the ending of Doraemon. (Although I know this long time ago, but I never get to see the drawings)
Here's the comic (chinese version)! English translation done by me.
In future, Nobita has become a great robot engineering professor. Suneo, Giant, and Hidetoshi (Smart fellow aka Nobita's rival) are discussing about Nobita and planning for a gathering. Suddenly, Hidetoshi asked them about Doraemon.
Suneo says it is impossible for him to forget Doraemon. Giant is angry about Doraemon's suddenly disappearance and this has made Nobita become a changed man. Hidetoshi then talks about this so-called Time Travel Effects (I dunno the term =.=, but i know abit of it)
Back in the past, Nobita was frustrated and he wanted some item from Doraemon, but he discovered Doraemon was not listening to him and couldn't move.
Dorami (Doraemon's sister) was on the Time TV and she suggested that his brother's battery was finished. Nobita thought there is a simple way to replace the battery.
Dorami stated if they replace battery, then Doraemon would lose all the memory because the backup-memory-system that was stored on Doraemon's ears was bitten by mouse long ago. Change battery = Lose memory.
But the 22nd century government has now banned time travelling which causes problem to present and future world. So Nobita couldn't get help from future robotic technician.
There are only 2 choices left: 1, replace the battery, then lose all the memories. 2, wait for a competent robotic techinician in future.
Nothing much to say here =.=
Nobita remembered the time him and Doraemon were together.
Nobita decided not to replace the battery, and planned to fix Doraemon himself.
Very rare scene, lol Nobita got no.1, AGAIN!! Shizuka asked him out to play but he rejected because he wanted to do more research.
Shizuka tried to get Nobita back, no matter how.
In future, Hidetoshi then says time travelling has changed the history when compared with Doraemon's era with THIS era.
Because the government knows the importance of Nobita that can change the history of the past and future, that's why future's government has ordered the present world NOT TO INTERRUPT with what's Nobita doing. (In short, if Nobita didn't have the decision to fix Doraemon himself, then there will be no Doraemon in future and future technology won't exist)
So ta-da, Shizuka and Nobita are repairing Doraemon.
Very very cool and touching scene, Doraemon is fixed after 35 years!
