We had the same worry, perhaps this is a little late but just in case I will answer. We are staying here at the moment and when we checked in we had the same question, the confusion comes from the word bathroom. The Japanese using this word literally as a room with a bath. So, in that case, each bedroom DOES NOT have its own bath/shower but DOES have its own toilet. Bathing is reserved for the onsen area it seems where in Japanese style one showers in the open area of the men’s or women’s onsen where one can indulge in the hot spring bath after your shower.