When you're playing Mizuki's (the student council prez) path, accept the footjob unless you want to feel like shit later. It won't make sense to you now, and it really don't quite make sense later, but you'll thank me in the end.
A lot of people on /a/ tend to say you should save Aeka's path for last, but that's so minor in the grand scheme of things. Unless you're a witless twat you are probably going to enjoy all the paths to a some degree.
Anyway, PLAY IT!