Talk:List of Special Research tasks/@comment-94.21.112.239-20180609205234/@comment-3123413-20180610082734

Nope, only tasks that could be already done before you get them are these related with achieving specific Trainer levels and Kanto medals, as you cannot get 25th level or Gold Kanto medal more than once.

So yeah, unluckily for you, you gotta find one more Ditto once you'll get 5th part with the Ditto task. Also, you can save Magikarp candies for the 6th part, but don't evolve that fish before you'll have this quest.