(Based after Phantom Planet & Seraph of The End season 2)
After he saved the world and showed the whole world his identity, Danny's life changed… but not in a good way.
Everything started to change, everyone started to treat him very differently. Jazz was now more like his manager then his sister, his parents were more like his weapon masters then playing the parent roll, Tucker being the mayor and all was being more of his advertiser then his best friend, and last of all Sam moved to New York City with her parents and grandma due to her father getting promotion and they tried to keep a long distant relationship but overall it didn't work out and they became just friends.
Danny couldn't take it anymore over how much his life has changed in such little time. So Danny went to clockwork wanting to have a new start but without tampering with the timeline itself to do it. Clockwork had just the way to be able to help Danny, and it was to have Danny travel into a different dimension and become that him. The only thing is that the memories that Danny has now will be replaced with the memories that his other self, but Danny accepted and decided to go through the portal to the other dimension.
Now instead of being known as both Danny Fenton & Danny Phantom, he is now known as Yuichiro Hyakuya, but he just goes by Yuu.