Wash before you soak. Sit on a stool, rinse thoroughly, then enter the tub. No soap in the bath water.
No towel in the tub. Leave your small towel on the side or on your head — never let it touch the shared water.
Bring your own gear. Most public baths have no showers, shampoo, or soap. Bring a small towel, washcloth, and toiletries if needed.
Donation appreciated. Baths are free but maintained by villagers (yunakama). Drop coins in the donation box (寸志 / sunji).
If it's too hot, add cold water carefully. Turn off the tap once comfortable — spring water is precious.
Hours matter. Not 24-hour. Most close 22:00 or 23:00. Respect closing time.