Vu Masami, Tore a rift into another dimension, due to an experiment gone wrong. Spending 1000 years in a primitive world, before managing to make another rift. He found that he returned to his home, but everything was different, Now with new creatures people had to fight for survival.

Granted, Vu was strong enough by then to live out his life exactly as he wanted, managing an obscure Inn down an overlooked alley. Living an Interesting life in the Inn of Knowledge.

(Mildly inspired by Xianshi Inn and Isekai Apocalypse Tropes)