Methinks the potion might actually work on a "two-way street" principle, i.e. not only do you fall in love with the first person you see, but said person will end up falling in love with you in turn.

MarqFJA87 said:

Methinks the potion might actually work on a "two-way street" principle, i.e. not only do you fall in love with the first person you see, but said person will end up falling in love with you in turn.

This feels more like just another of mochi's yuri excuse plots (not that I mind). But to the extent that there is any kind of plausible theory, I think it's that the idea that you turn someone on can be arousing all by itself. Also dark-hair may have been a bit bi to start with.