In Japan, onsen are hot springs and the bathing facilities and traditional inns around them. There are approximately 25,000 hot spring sources throughout Japan, and approximately 3,000 onsen establishments use naturally hot water from these geothermally heated springs.

A ryokan is a type of traditional Japanese inn that typically features tatami-matted rooms, communal baths, and other public areas where visitors may wear nemaki and talk with the owner. Ryokan have existed since the eighth century A.D. during the Keiun period, which is when the oldest hotel in the world, Nishiyama Onsen Keiunkan, was created in 705 A.D. Another old ryokan called Hōshi Ryokan was founded in 718 A.D. and was also known as the world's second oldest hotel. Such inns also served travelers along Japan's highways.