Summary: One of the problems encountered in face-to-face communication involves conversational imbalances among the participants caused by differences in conversational interests and social positions. It is common for us not to be able to communicate well with an unfamiliar person. On the other hand, old customs in the real world, such as the Japanese tea ceremony, effectively use physical artifacts to enable smoother conversation. In this project, we designed two communication systems that facilitate casual communication using physical/digital artifacts, such as a meal and text-chat, in order to clarify that real world communication can be supported by digital technology. The first system, called the “Communication Grill," connects a grill for cooking meat to a chat system. The grill is heated by the chatting activity. Thus, people must continue conversing to roast the meat. The second system is called the “Communication Salon.” It is a computer-enhanced tea ceremony with a chat screen displayed at a tearoom. Using these systems, we conducted user evaluations at SIGGRAPH and other open events. Based on the chat logs at these events, we found that conversational topics gradually shifted from topics about the systems to more general topics. An analysis of these chat logs revealed that the participants began to communicate spontaneously using this system.