Survey pinpoints causes to plastic umbrella waste in Tokyo

Nature Innovation Group Co., Ltd., the operator of the umbrella sharing service i-kasa, released the results of a survey regarding forgotten and discarded umbrellas in Tokyo offices. The study focused on office workers in Tokyo’s 23 wards and revealed that 71.6 per cent of respondents have left umbrellas at their workplace.

The primary reason for leaving umbrellas at the office was simple forgetfulness, cited by 49.4 per cent of participants. However, the data suggested specific urban challenges in Shibuya that differ from the wider Tokyo average.

In Shibuya Ward, 84.1 per cent of respondents have left umbrellas at their workplace, with 42.8 per cent of workers stating they leave umbrellas behind frequently. Often the reasons came down to social plans after work or the desire to avoid carrying bulky items on crowded public transport. These findings suggest that the physical burden of carrying an umbrella often outweighs the perceived value of the item.

The survey also identified a high reliance on disposable plastic umbrellas despite already owning one. Approximately 66.8 per cent of workers in the 23 wards admitted to purchasing plastic umbrellas even when they already owned functional ones at home. This trend was most pronounced in Shibuya, where 87 per cent of respondents had made such purchases. The main drivers for these transactions were the distance to destinations and the desire to avoid the stress of getting wet. In addition, Shibuya’s data showed 32.5 per cent of respondents noted a lack of available rental options as a direct reason for buying disposables.

Abandoned umbrellas remain a visible waste issue in the city. Over 60 per cent of workers across Tokyo reported seeing discarded umbrellas in the streets, a figure that rose to nearly 80 per cent in Shibuya. It is one of the key motivators for Nature Innovation Group’s 2030 Zero Disposable Umbrella Project to address these concerns. The company continues to expand its umbrella sharing network of rental spots, particularly in high-traffic areas like Shibuya where the demand for flexible, ownership-free solutions is greatest.