It could be the concept was to have the MC be a Virgin until near the end of the game, where he would end up with one ( or many ) of the girls ( and just like every other of this dev games, I take it there were never a H-scene for the MC, although there were happy ending, but no H-scene ).
It may be that initially they wanted to give a curse item to the MC to never have sex, the unremovable cursed pants, but then they realize, if they did that, he will have trouble shitting and pissing, so they changed it to holy power of erectile dysfunction or something, who knows...
Anyway, really hoping for the game to be released in May THIS YEAR, but.... Haaaa~ah....