The two sentences you see provided above are great ways to express to your listener that a certain hot spring is for both men and women. In the second sentence you will see the adjective unisex. Unisex means that something is designed for both men and women. You may see this word at a clothing store or on the door of a public bathroom.
We don't have one word for saying men only, women only or both.
You have to ask this as a question and it can be said in a few different ways.
e.g.
Is it women only in the baths?
Is it mixed in the baths?
Are there men and women in the bath?
Hope this helps
Jane :)
男性のみ、女性のみ、またはその両方を表す一つの単語はありません。
これは質問として聞く必要があり、さまざまな聞き方ができます。
【例文】
Is it women only in the baths?（女風呂ですか？）
Is it mixed in the baths?（混浴ですか？）
Are there men and women in the bath?（混浴ですか？）
お役に立てば幸いです。
Jane :)
When you want to explain that an "onsen"is a where both men and women can bath at the same time, you can say the same time:
-co-ed bathing spring
-A bathing spring where both men and women get in.
-This bathing spring is for both men and women.
混浴の "onsen"（温泉）を説明したい時は、次のように言う事が出来ます。
【例文】
-co-ed bathing spring
（混浴温泉）
-A bathing spring where both men and women get in.
（混浴温泉）
-This bathing spring is for both men and women.
（この温泉は混浴です）
Unisex - suitable for both men and women.
Communal - shared by all members of the public.
A: Is this spring unisex?
B: No, only women can use this spring, there's a communal spring in the next town.
Unisex - 男女両方が使える
Communal - 共用の
A: Is this spring unisex?
この温泉は混浴ですか？
B: No, only women can use this spring, there's a communal spring in the next town.
いいえ、女性だけがこの温泉を使うことができます。混浴の温泉は隣街にあります。
In the UK, any venue offering facilities to both men and women would be described as 'mixed'.
Eg 'John attends a mixed school.'
A public bath in the UK would by default be offered to both men and women in a combined swimming environment, so it would not be necessary to mention anything other than the word 'public.'
イギリスでは、男女共用の施設はすべて、'mixed'（混合）と表せます。
【例】 'John attends a mixed school.'
［訳］ジョンは男女共学の学校に通っています
イギリスでは、プールに公共浴場（public bath）がある場合、最初から男女両方に提供されています。ですから、'public'（公共の）と言えば、他に何も加える必要はないと思います。
Many spas and hot springs must specify when they are for men only, women only or for all genders. Also with bathrooms, sometimes, we can say "it is for all genders" or also "it is a shared bathroom". Also a mixed gender bath or a mixed gender hot spring. You can also say, "This spa is for both men and women." "The structure is for both genders/a mixed gender facility." "Men and women are not separated, they are allowed together in the same areas."
スパや温泉が男性のみ、女性のみ、あるいは男女共用の場合、それを明示しなければいけないでしょう。
また、バスルームの場合、次のように言うことがあります。
"it is for all genders"（男女共用）
"it is a shared bathroom"（共用バスルーム）
また、
"a mixed gender bath"（混浴）
"a mixed gender hot spring"（混浴温泉）
次のように言うことも出来ます。
"This spa is for both men and women"
［訳］このスパは男女共用です
"The structure is for both genders/a mixed gender facility.
［訳］ここは男女共用の施設です
"Men and women are not separated, they are allowed together in the same areas."
［訳］男性用、女性用には分かれていません、どちらもご利用いただけます
If you are wanting to say it is for men only or women only then it is simply 'men only' or 'women only' but if both men and women are allowed then you could say it is 'unisex' meaning both men and women are allowed in.
アメリカ合衆国 
イギリス 
南アフリカ 
