Harassment is not nice, but it is not illegal unless it happens in the work place.
As far as criminal law is concerned sexual harassment is illegal in the workplace as Buck noted. It is also illegal in public schools (I'm not sure about private schools). While criminal law doesn't seem to to be applicable to the situation brought up by Tom28, civil tort law does have possible application in that the person(s) being harassed may be able to sue the school's owner(s) and/or the instructor under battery or assault tort definitions. (Links below)
For a detailed discussion of how tort law may be applied to cases of sexual harassment not related to the workplace or school, see "Sex, Women and the Law" by Rosemarie Tong.
A lawsuit of this nature can, if successful, put a thriving dojo out of business thereby depriving all students the ability to learn and train.
Buck, it seems that you are suggesting that:
A. The female students who are being subjected to this unwanted attention should, since (as you have noted repeatedly) times have changed, either suck up and live with it or leave, and
B. Other students such as Tom28 should stay out of it and let the sensei work out his "personality defect problem" for himself.
Far from encouraging the sensei to examine his "personality defect problem", this enabling behavior will most likely guarantee that the behavior will continue thereby putting the dojo at risk of what could turn out to be a crippling lawsuit.