Men or women
Which entrance would you use?
Most onsen (hot springs) and sento (public baths) usually use the same noren colors and at the same time the sex is specified written on them, however if you can’t read Japanese this could be a problem.
Another possibility is that the baths are mixed (混浴 – こんよく: konyoku) in which women and men share the same ofuros. Although mixed baths are less and less common and you can only find them in very traditional ryokans.