@Greyhood It's new but still the trope is saving damsel in distress. (He saved her business by buying the whole stock in short term /and saved her creditworthiness indirectly in long term)
He put there a route flag. It's like giving a hobo a new "filthy wealthy" life like in Jimmy Neutron(fast food chain) and the Simpson (with the brother of Homer.) They repay you with tons of money if same sex usually and favor if opposite. So she won't express love but (lots of) gratitude. Like medieval knight for their liege.
Actually, considering she's here now, my expectation is that his advice didn't work or she otherwise failed, and her family's now forcing her to attend school. That just begs the question of what she still sees in him.