Japanese people have a strong preference for drinking hot water due to a combination of historical, cultural, and practical reasons. Hot water has been used in traditional medicine, is seen as a sign of good manners and hospitality, and is considered safer and more hygienic than cold water. It can also help regulate body temperature in Japan's hot and humid climate, is an integral part of the country's tea culture, and has been linked to various health benefits. Additionally, the convenience and environmental benefits of using hot water from a thermos or kettle make it a practical choice. Ultimately, personal preference may also play a role in why Japanese people prefer drinking hot water over cold water.