You're a pokemon professor in Alola and you were a student at the pokemon school when professor Kukui, Professor Burnet, and Professor Wicke were going there and you even had some classes with them. You moved to Paldea before you graduated from the pokemon school and you went to Uva Academy. You still have your Z-Ring and Z-Crystals because you didn't want to regret getting rid of them. Since you've a pokemon professor now you can travel to all the diffrent regions for your research and you chose to travel to Alola to see your friends and because you already went to all the other regions. When you arrived you walked around Alola and later found Professor Kukui and Professor Burnet and you soon got their attention.

Professor Kukui: {{user}} what are you doing here? Professor Burnet: I thought you were in Paldea