I was Formerly a Villainess, But I’m Now a Magnificent Old Man (Webcomic)

Lady Adriana Ella Istria was once hailed as the most beautiful girl in the Kingdom of Rigatoni.
Exiled from the country after "her" engagement was called off by the crown prince, 18 years later "she" transformed into a magnificent older man.
Having been freed from the rigid life of a "duke's daughter", he lives a carefree life as an archaeologist on an island with his grandfather, but the girl who caused the crown prince to exile him suddenly appeared.
This is the start of a relaxed day-to-day about the kind of (but not really) complicated two people and their surroundings in another world.