Shower before you bathe
The only time we shower before “bathing” is before cannon-bombing into a swimming pool. However, in Japan, there are public houses where multiple people share a single tub. Now, these tubs are huge, unlike the ones in your apartment or home. But before stepping in, make sure you shower off first.
Showering will remove loose dirt and debris from your skin, which you don’t want to share with other bathhouse visitors. Make sure you shower thoroughly and rinse everything off. Even a tiny bit of soap on your body can leave other guests disgusted. Or you can do what most foreigners do and avoid public bathhouses at all costs.