My master was killed by Darth Sidious. Don't worry, Mara, as your new Master, I'll protect you to the best of my ability, even if I have to give my own life.
—Jeff'ia to Mara on Tatooine.
After Order 66 was issued, Jeff'ia was able to escape the 115th Battalion and took refuge on Tatooine where he knew that the Empire would never come looking for surviving Jedi and upon arriving on the surface, he had met Mara Tachia, a surviving Jedi Padawan, and took her in to guide her on the rest of her training into Knighthood.
But Master, is that even allowed?. I mean the Council is supposed to elect its own members, right?. The Chancellor can't do that.
—Jeff'ia to Windu upon learning about Skywalker being on the Council by the request of Chancellor Palpatine.
Battle of Rhen Var
Jeff'ia Nakamura was assigned to the 115th Battalion during the last year of the Clone Wars and was told that they were in an active conflict on the Outer Rim world of Rhen Var. His master then organized reinforcements for clones and Jeff'ia was going with the reinforcements and get familiarized with his new unit of clone troopers.
- Star Wars: Alliance Civil War (Non-canon cameo appearance)