The origin of the bathtub can be traced back to ancient Japan with the furo or ofuro. These tubs were originally made from wood, but have moved on to acrylic, stainless steel, tile, and even glass with the advent of modern technology.
The ofuro is much like a modern western tub with a few differences. These tubs are a bit smaller and deeper with a squared body instead of the slight round aspect of today’s modern tubs found in the west. The original ofuro tub was heated with a wood burning stove under the tub itself, but with today’s technology, they have a system of filters and recirculation techniques that reheat the water, keeping it nice and warm for you.
In Japanese tradition, the eldest male in the family would take the first bath followed by the rest of the family in order of seniority. When all the bathing was complete, the laundry would be done with the remaining water.
Ofuro were made mainly for relaxing in, so the entire family would have to be clean before getting into the tub as it is considered rude not to. These were the start of the Japanese spas that have become so popular in the last few decades.
Japanese bathrooms are usually extremely small and more akin to a walk in shower than a western bathroom aspect. They usually have a stool where they can sit and wash their hair and body before getting into the tub. There may be a small faucet or shower head that they can use to bathe with.
There are still many places in Japan that have public bath houses that people go to instead of having one in their own homes. These bath houses are always segregated between male and female and no clothes are allowed, including bathing suits.
Bath houses became extremely popular in Japan after World War II, but have since fallen to the side as more and more people are able to have their own bathrooms built in their homes. With less customers coming to a traditional public bath house, there isn’t much need for them, and you don’t see them as much anymore. But they are still there and still used to this day.