We propose a supervisory system that deals with actual situations and social aspects of users in ubiquitous computing environment in this paper. To realize a gentle and safe supervision, we have to consider social relationships between observers and the watched person to give adequate level of privacy to the services. We propose "uEyes", a ubiquitous supervisory system that introduces a new feature for the supervision, i.e., Social Context Awareness. By using this feature, environmental information acquired from real world and knowledge on social activities of people are integrated effectively. From experimental results using a proto-type of uEyes for supervising elderly people, we show that the social context awareness, as well as other components of the system, effectively works to support the supervision.