How convenient that the girl who was a history geek was transported back in time to the period she knows best.
How convenient that she encountered the one person who would actually believe her and somehow employ her on the spot.
How convenient(for the reader) that her new clothes still somehow...
I am well aware. "Hey average guy, you need to have sex with all these girls to replenish their mana" remains as one of the most pathetic premises I've seen
That's the point, the trade was too good. Take a million of my future lives, what do I care? Even the future lives themselves won't care since they won't exist in the first place...