You may have seen posts or photos online showing water bottles placed around the home in Japan — on shelves, near doors, or in corners — and wondered what it’s all about. This practice isn’t about forgetfulness or a lack of refrigeration space. In fact, it’s rooted in traditional beliefs and practical thinking that many Japanese households still follow today.
A Tradition with Roots in Folklore
One reason people place water bottles around their homes is connected to traditional Japanese folklore. In some regions, it is believed that placing water in specific spots can help ward off insects like flies and mosquitoes. The idea goes that the light reflecting through the water confuses or repels bugs, keeping them away from living spaces. While not scientifically proven as an insect repellent, this method has been passed down through generations and remains a cultural practice in some areas.
Cooling Without Electricity
Another practical aspect of setting out water bottles — especially during the hot summer months — is passive cooling. Before air conditioners were widespread, households used every available trick to keep cool. Placing bottles of water in strategic locations allowed the water to slowly absorb surrounding heat, slightly lowering the temperature of nearby air. Even today, some people prefer this gentle cooling effect to reduce reliance on electric appliances.
Sense of Refreshment and Daily Mindfulness
In Japanese culture, there is often an emphasis on harmony with one’s environment and awareness of small daily rituals. Seeing a clear bottle filled with water can provide a subtle sense of calm and refreshment. To some, it symbolizes purity and simplicity, qualities highly valued in traditional Japanese aesthetics. Rather than storing every bottle in the refrigerator, leaving water out becomes part of the rhythm of everyday life.
Not All Households Do This
It’s important to note that this isn’t a universal practice in Japan. Many people do refrigerate their water, especially in modern urban homes with easy access to chilled drinks. The balancing of tradition and convenience means that practices vary widely from household to household.
Does It Actually Work?
From a scientific standpoint, placing water bottles in the home has limited proven benefits. Reflective water may deter some insects in controlled scenarios, but it’s not a replacement for screens or repellents. Similarly, water left at room temperature or in shaded areas will only have a minimal impact on ambient temperature when compared to modern cooling systems.
Final Takeaway
Placing water bottles around the home is a blend of folklore, practicality, and cultural tradition. While it may not replace refrigeration or modern pest control, it offers a window into everyday life and long-standing beliefs in some Japanese households. For many, it’s a reminder of simpler times — and a symbol of reconnecting with nature and one’s surroundings.
