Two different baths here. The one in the betsukan, father down the hall, is bigger and better. Nice shallow bath in relaxing dark brown and black. No real rotenburo, but there’s a nice atrium like area with a window that opens into a garden. The sauna is new, as of 2013, and has that great new sauna smell. The older second bath is much smaller and older with a garden view. Can get very crowded if a group of guests use either of the baths all at once. The water feels dry and powdery in the bath but smooth out after you get out. Great for relaxing before a flight, or washing off after a long flight.
You can drink the spring water here. There’s a cooler in front of the elevators. In the baths there’s also the excellent Bayu shampoo, conditioner, and body soap.
The hotel connected to these baths is basic, but clean and very comfortable. It has pickup and drop-off service to Kansai Airport, Rinku Premium Outlets, and nearby train stations.

No day use for this bath, you need to rent a room to use the facilities here but its a great option if you are flying in or out of KIX.