Bathing is a big deal in Japan, it is one of the great local pastimes, and Japanese-style bathing is always a pleasure, whether in a public bath (sento), hot spring (onsen), or simply in the bath in your own home.
Ritual purification is an important part of Shintoism, and having a clean body is also a key principle in Zen Buddhism. As these are historically the two main religions in Japan, cleanliness in general is ingrained in Japanese culture.
Respect for the bathing ritual is evident from the fact that every Japanese house has a room exclusively for bathing and toilets are separate. Bathing is seen as an activity less to wash and more to relax.
Before bathing one must shower first, especially when at a public bath or sharing your bath with family members at home. A great example of the importance of bathing is shown in the picture above, Yusa is bathing in a barrel while on a short camping trip in a forest in episode 5 of Charlotte.
All the family may bathe together, or possibly use the same water one after another. Friends may even bathe together at home. To keep the right temperature throughout this process, electronic panels have been developed to display the bath temperature and so it can be kept warm for long periods.
Bath covers can also be used, especially to keep the heat in when reusing the water. Traditionally the water was kept for washing clothes the next day. The bathroom is often set up as a wet room, with a drain set in the floor.
Then the shower may not be in a stall, just placed near the bath, and it doesn’t matter if the bath overflows. The square Japanese bathtubs with straight sides are known as furo, or the polite form, ofuro.
Many small apartments may not have a bath in each unit, there may be one large shared bath for the entire apartment block or the residents may frequent a local public bath.
Japan has many natural thermal hot springs, and spas often offer several different bathing experiences, like different temperature baths, foot baths and even sand baths. In these facilities you rent yukata and relax in the full facilities.
Other public baths are more simple, just places to bathe if you don’t have a bath at home. Public baths are mostly gender separated but some occasionally offer a mixed bathing space.
This is because bathing is done completely naked and even showering areas may be communal (no individual stalls, as shown in the scene above from I Couldn’t Become a Hero, So I Reluctantly Decided to Get a Job).
The opportunities for ecchi are numerous, and anime often capitalises on this. Anime is full of examples of people going into the wrong bath, getting glimpses through walls, or overhearing the intimate conversations of the opposite gender.
Large towels are also generally not used, so the only potential covering available is a small towel. These are often balanced on the head while in the bath.
Many inns pride themselves on their baths. Spacious rooms can hold a larger private bath than most will have at home, or the inn may house a hot spring bath or larger bathing space that all the guests can enjoy.
In Kakuriyo -Bed & Breakfast for Spirits- it is noted that many come to the inn specifically for the baths the caretaker draws. Bathing is a central part of relaxing for many, and so a vacation will need to include a luxurious bathing experience.
Since bathing is an everyday activity, it comes up a lot in anime. If you are interested in Japanese baths, look up Orenchi no Furo Jijo, an anime about a merman named Wakasa who lives in a bath. Much of the bathroom set-up is shown and explained.
Also if you want to know more about public bathing, the process is explained in detail in the seventh episode of Denki-gai, as some of the employees of the bookstore who go to bathe together haven’t been to a hot spring before and are unsure of the etiquette.