If you expect a fancy place to stay - that's not your place. It's very simple, typical Japanese house, with matts on the floor and the traditional sleeping. The owners speak only Japanese, so if you don't know this language, stay away.
Shared toilets and showers - there's a problem if there are too many people taking showers at once. No bad smell, but rather small toilets. Thin walls. Heater in our room saved our lives when we got soaked wet.