Neya was one of my favorite supersento then they turned off the hot spring, with no reason given. Maybe it got contaminated. To replace the spring water they have treated the water in the main rotenburo to make it feel soft, so it is not that bad. I just cannot feel right paying the same price for no natural spring water in this supersento. It is a very well designed supersento however. There is a great selection of temperatures in the indoor baths including a warm heavily carbonated bath. Good place but ¥800 on the weekends for no spring water is a bit steep.

Update January 2020:
They turned off their hot spring well for a while but were bought out by a different company, changed their name and seem to have reconnected their hot spring.