A ryokan embodies the very essence of Japan and is surely the accommodation of choice if you wish to personally experience the uniqueness of Japan - the architecture, lifestyle, nature, traditions and culture. Staying at a Japanese ryokan offers a splendid opportunity to familiarize yourself with the spirit of Japanese hospitality and graceful customs that have been passed down over many generations. When you visit Japan, be sure to experience and enjoy this classic Japanese hospitality. There are some 55,000 ryokan in Japan, of which 1,300 are quality establishments belonging to the JAPAN RYOKAN ASSOCIATION (Jpnz., "KOKUSAI KANKO RYOKAN RENMEI". Its members must meet a host of regulations for cultural aesthetics, privacy, and hygiene before becoming members.
In a ryokan you can experience the elements of Japanese culture and customs: living in a room with Tatami (straw mat) flooring, changing into a typical Yukata (robe) after taking an Onsen hot-spring bath, sleeping on a Futon (bedding) put down directly on the Tatami floor.

and......
sometimes an ad for one of Japan's best ryokan on this page

So that is their proper name. In Mie, they were frequently referred to as 'Onsen', quite literally "steam". Always good to know something's true name, you may have just been critical in helping me avoid a kotoayamari. Arigato, Craig-sensei. ^_^

No worries, Hoop
(not really a Japan Sensei.. just pass on what I learn here as time goes on only had two years here so far so really only a beginner )

Actually the onsen are the places that have the hot baths (sometimes natural, sometimes not) whereas the ryokan are the traditional inns.

Sometimes the ryokan have onsen and sometimes the onsen have ryokan.. but not always.

Sometimes modern hotels and health places have onsen also...

Hope that helps

(thanks for posting.. always value your input )

Ryokan are great but dont be planning any romancing in them.. the walls are too thin!!!!!