This article provides comprehensive guidance on what to do in a Japanese public bath, known as "onsen." It emphasizes the importance of researching the specific rules and regulations of each onsen before visiting, as well as entering the correct gender-segregated bath area and showering thoroughly before entering the hot water bath. The article also suggests trying different baths, taking breaks to cool down, drinking plenty of water, and enjoying other amenities offered by onsens. Overall, visitors can have an enjoyable experience if they follow these guidelines and respect local customs.