Many mobile devices are a necessity for modern people. For example, a smartphone plays almost the same role as a human brain in everyday life, but it becomes a tool for work and sometimes a toy for play, using its various functions. People can use the smartphone's various functions and roles with ease and without any manuals. Businesses are focusing on the user experience and simplifying the interface for intuitive use. At the same time, the design has been simplified and minimized to reveal the characteristics of the product. A design flow that simplifies the design gradually and intuitively is called minimalism. This tendency is the phrase "Less is More". This excludes most unnecessary decorative elements in the design means the design tends to emphasize the property itself. However, in the field of marketing, research on the impact of such design on consumers is limited. This study examined the influence of minimalist design in terms of conveying the meaning of products to consumers rather than the aesthetic aspects of design, which is the existing research flow in marketing design. In this process, we will focus on the concept of playfulness and the curiosity of consumers in order to explain the process of designing mobile device to convey meaning of toy as well as meaning of tool to users. Therefore, the purpose of this study is to define the effects of playfulness perceived by consumers on the design characteristics, and to examine the effect of these toy effects on consumer attitudes. In Study 1, we examined the effect of the level of minimalism perceived by consumers on consumer attitude by using notebook as a experimental stimulus. In Study 2, the experimental stimulus was changed to tablet PC in order to generalize the study results. The results showed that the minimalism design of mobile devices affects consumer attitude, playfulness plays an intermediary role in this process, and consumers' curiosity tendency has a moderating effect.