The purpose of this study is to clarify the process of introducing the Internet to the Kendo world and investigate the impact of expanding of the viewing and communication space. As for the impact, the major findings are as follows. Kendo has become a sport for audiences, and Kendo tournaments have become like other sporting events as a result of the Internet broadcast of Kendo matches. Therefore, audiences began to focus on the playability of Kendo rather than its cultural aspects. And it is difficult for audiences to determine the mental state of Kendo players, so they tend to watch just the physical aspects and evaluate Kendo players on that basis. But Kendo's change to a sport for audiences to watch, the focus of their attention becoming mainly playability, and disrespect of the cultural aspects of Kendo have not been considered good by the Japan Kendo Federation (JKF). For example, the JKF has emphasized the cultural aspects of Kendo and explained that Kendo is a martial art that has different characteristics compared to most other sports. Kendo is also a traditional culture characterized by vertical structure and hierarchy. On the other hand, many Kendo players of different ranks and ages are able to communicate with each other at various levels, such as local, regional, national, and global, using the Internet. In such horizontal and grassroots communication spaces, users exchange and share various pieces of information about Kendo and occasionally hold training events based on agreeing to participate through the Internet. These activities embody the philosophy of the Kendo world that promotes exchange and mutual understanding between Kendo players, but the actual situation that we observed with such uncharted and flexible activities is not acceptable to the Kendo world, which is characterized by vertical structure and hierarchy.