Operation - Propose is the twelfth chapter of Doraemon Manga.
The chapter starts on the day of the 12th anniversary of Tamako Nobi and Nobisuke Nobi. Nobisuke comes back home early for the party. Nobita asks both who proposed first, both claim that other one proposed first, which then leads to both of them arguing and fighting later. Doraemon uses Lie Detector gadget, to see who is lying, but both are telling the truth. Doraemon and Nobita use the Time Machine to see their parents 12 years ago.
At the past Tamako was waiting for Nobisuke for a long time, he ended up blaming his lateness on the watch given to him by Tamako as a gift. She leaves and goes off, but this was just her teasing Nobisuke to teach him a lesson, afterwards she dicides to go back to Nobisuke, but ends up mistaking someone as Nobisuke, on the count that she wasn't her glasses. She realised that she had made a mistake, and went off, On the other hand, Nobisuke was with another cute girl (who turned about to be his Younger sister). Finally, both were displeased with the other. Afterwars Nobita, soon begins disapearing, so Doraemon uses the Imitation Dummy to imitate both of them to make the other propose first. (This is the reason why the lie detector did not work before).
Nobita and Doraemon go back to their present time. Both end up finding their parents outside, deciding it does'nt matter who proposed first as both watch the moon together.
- Tamako and Nobisuke propose on November 3rd, 1954.