So, this had me thinking... which is better? Assuming that there's a certain item/substance that prompts growth... should the girls be able to get it themselves? Easily? With difficulty? From a hapless male protagonist.
I prefer stories where the female characters are not in complete control of their own growth and don't get psycho from their empowerment.
I have three favorite tangents to this type of storyline (and to the law of unintended consequences).
One is where the nerdy male friend whom secretly causes the growth of the female character(s) underestimates the power of his action thereby causing the girl(s) to grow more than he had intended.
The second is basically the plot of "Compounding Interest" where the girl wants to grow, grows more than intended, but doesn't seem to mind the miscalculation at all and uses it to her advantage without going crazy.
The third fits into PT's question. It is a combination of one and two where her initial growth is caused secretly by a friend but then the girl finds out and would like a bit more. The friend is not "hapless" but could be either reluctant or eager to help or out of formula.
Tschuss!
Hunter