I'm giving this manga 2 more chapters to clear things up. Because this has gone on for more than two months of our time. Either the mangaka is winding down for a finish or they're dragging the story out.
Pardon, but it is 'thine umbrella' and 'mine/my umbrella'
I get it though. Possessive articles are the trickiest bit of Early Modern English or Elizabethan era English.