Online communication is rapidly replacing face-to-face group communication in real space due to COVID-19 pandemic. However, in online group communication, when the number of participants increases and the entire members are arbitrarily divided into groups, some participants find it difficult to decide which group to join; it becomes difficult to see the topics discussed in other groups. To overcome the problem, we are developing a system called EVEA to assist the online group communication for text chatting. In EVEA, the discussed topics and the activeness of discussions based on our metrics in other groups are provided to participants as a hint for deciding which group to join. In this paper, we describe an overview of EVEA and explain how the system is designed.