Private bath booking at Yurari Onsen

Hi, does anyone know whether I need to book in advance if I'm going for a private bath at Yurari Onsen?

Can anyone share his/her experience of the private bath at Yurari Onsen?

As additional information, I'll go there on weekend.
If I need to book, does anyone have the link in English?

Can anyone help me with this?
Thank you in advance..

Do you mean Yurari near Saiko?

http://www.fuji-yurari.jp/spa.html

The Q&As on their site say you do not need to reserve for private baths. Further you can not reserve it. They operate them as "first come, first go" policy.

http://www.fuji-yurari.jp/qa.html#dialog-07

Note that you can use private baths only when you stay at Fuji-Midori-no-Kyuuka-Mura.

http://www.fuji-yurari.jp/spa.html

Hi, thank you very much for your help.

Yes, I meant the one near Saiko.
Thank you.