The use of reusable cups as a solution for the issues on waste and environment destruction has been brought up and is not that of a new topic. Although this has been an issue for decades and there had been suggested solutions, we still could not solve the problem until now. The issue is getting worse with the recent expansion of the hot beverage business market.

I believe we have to change our perspective on how we view the problem. It's not that people can not recognize or are ignoring this problem, they just have a hard time putting it into action. It is necessary to find out if there is a more fundamental problem in the series of actions required to the people to solve the problem. In this perspective, this research first checks whether the customers of the hot beverage business, that use the largest amount of disposal cups, are aware of the issue. Next, if they are aware find out what stops them from taking action. Finally, by proposing new solutions for the causes, help the consumers actively reduce the consumption of disposable cups and rather use reusable cups instead.

In order to approach the goal that was mentioned beforehand, we have visited a local beverage shop that had the biggest crowd of customers and conducted a survey and interviews. Through this process of involving in the scene, it was able to define the substantial problems, while also applying the most representative behavioral change theory, 'Stage of Change Theory'. This theory classifies and defines the consumers' behavior in stages and provides a solution for an appropriate behavioral change in each stage. It proposes an effective guide line on how the consumers should determine what to do. Also, find the elements that can be solved with the designers' view out of a variety of solutions that can come out of each stage. After defining the elements provide a solution with design.

We can define the role of the design area apart from other various academic approaches of behavior change of people through this process. I hope design is not just an assistance for behavioral change, but that the designer has a basis and motive to actively involve in each stage of behavioral change. But first, with a more certain form of design motive in the topic 'hot beverage business', draw the consumers' changing behavior and provide various motivations that the change can last, increasing the use of reusable cups.