We believe that humanoids will take an active part in our daily lives in the near future as important media, since a human-size humanoid enables people to more easily accept a sense of humanlike expressions or emotions, wishes, and so forth in addition to capabilities of other media, such as the ability to collect and provide information from the Internet and via ubiquitous sensors connected through a network. Once this time arrives, humanoids will be expected to have the social skills necessary for interacting with people in addition to the ability to carry out their own tasks. We call an interaction that increases familiarity and makes communication smoother a “social interaction.” We have recently developed a human-size humanoid, called “Robovie-IV.” Robovie-IV features interaction abilities such as the ability to chat vocally, which are intended to be “social interactions.” Using Robovie-IV we have conducted an experiment in which it interacts with people in an everyday office environment. This paper discusses the design requirements of Robovie-IV and introduces an overview of its hardware and software architectures. Then, the experimental results, discussions, and conclusions are presented.