@thrembs being "male" is not relevant, if they identify as a girl then thats whats relevant, and point is, we dont actually know if Tsubasa considers themselves a girl or a boy, its hard to say with what we know so far, and they dont actually say either way.
secondly, there is no sexual harrassment here, using a bathroom is not sexual harrassment, considering how Tsubasa looks, it would probably end up as actual sexual harrassment if they use the mens room (they look like a girl, entering the mens room is a bad idea).
but lemme guess, your one of those transphobes yes? the fact you consider Tsubasas birth sex over their possible identity (which is still unconfirmed) and consider using the womens restoom to pee is somehow sexual harrassment when literally zero harrassment occured is quite telling