It sounds like you're interested in the series (The Great Sage Who Returned from Another World Still Intends to Live Quietly). This story is a popular "returnee" fantasy about an overpowered protagonist trying (and failing) to lead a normal life in modern Japan.
A post highlighting the plot, the protagonist Saito’s charms, and why readers love this "reverse isekai"? It sounds like you're interested in the series
A deep dive into the story's start—Saito's return after 19 years, his reunion with his childhood friend Kanako , and his run-ins with modern-day magi and yakuza? the protagonist Saito’s charms