A Yuasobihiroba sento. Fukuzumi has a great selection of baths set up almost like a playground. When they say Yuasobi they mean it. Yu means hot water and asobi (遊び) means play.
The two different baths change daily. One side recently was remodeled and the salt sauna was replaced with a charcoal one. Using the expensive charcoal from southern Wakayama no less. The building that Fukuzumi is housed in is rather large, but the actual bathing area isn't too big. Even though it's rather hidden in the middle of a residential block, It's hard not to find this sento because of the giant radio antenna protruding from the top of the building and all of the neon pasted to the sides.
Like all of the Yuasobihiroba group sentos you'll have a great time and get to experience wide selection of different baths in a fun and relaxing environment.