My HiME's ending wasn't really a reboot, just a very badly executed ending.
Everyone still theoretically remembered everything and everything still happened, it's just that the ending basically completely ignored any consequences of all that, followed by an extremely underwhelming final battle.
Reboot was a poorly chosen word by me. What I was really annoyed by was that up to that point, My HiME had a rather well written story and it was so so so very close to having one of those rare really quality runs to the finish.
I have to say that the anime that has had the most satisfying ending for me ever is shin sekai yori. I felt that whole story was incredibly well written and the ending did not let me down.