For the losing heroines.

It depends if she's a late bloomer. When I was a supervisor in a grocery store a long time ago we had this boy/girl friend couple that worked there and she was flat as a board when we hired them. Two years later they broke up, though they never went into the details she bloomed going from flat to my guess big C to small D cups, and I bet it got her more attention therefore she most likely dropped him for another guy. Since this girl is just a year older than them and they're in high school, so she still has potential to grow as well as the rest of them though I feel Miyamoto bloomed early (it seems to me that's how most extroverts are).

It seems at times it's a combination of marketing and timing, some of these authors seem to fall ill at the wrong times dragging the series into the axe or no resolution (cough "Iris Zero" cough).