Bringing a towel for day onsen

Hi,

For Day Onsen Trips, must I bring my own towel? I have only been to the onsen in Kurama.

If I were to go for a hotel just for the onsen, must I bring my own towel?
How about Ibusuki sand bath?

Kurama
Day course
\ 2,500
Towel, bath towel, yukata rental is included in the price.
I put in the main building and open-air bath.
Open-air bath course
\ 1,000
Towels are 200 yen sold separately. There is also a bath towel rental.
I put one in the open-air bath.
http://www.kurama-onsen.co.jp/plan01/index.html
http://www.kurama-onsen.co.jp/plan01/index.html

For Day Onsen Trips, must I bring my own towel?

No, you don't have to bring your own. But you can save money if you do. Otherwise they are typically on sale for 200-300 yen at the hot spring, or rentals might be included in the price of admission.

How about Ibusuki sand bath?

Towels are not included but on sale at the facilities.

You can buy a face towel 200-300 Yen(non-return), can be rented a bath towel 400-500 Yen(return).

yes, you may.
When we go with family, they always take their own towels, with enough for us
BUT
if we go on our own, it�fs not too expensive to hire one, so we do. (beats wet towels in luggage...lol)

As mentioned, you can buy cheap towels at the onsen, but keep in mind that they are usually just thin face towels. That is enough to wash your body with, and then to wipe your body with before putting on your clothes again. But if you need a big bath towel, it's safer to bring your own.