A dual magnetoencephalograph (MEG) system would be a powerful tool to analyze brain relating to interpersonal communication. However, because individual MEGs are rarely located in close proximity to one another, only a few dual MEG systems have been developed. We have recently developed a dual MEG system by connecting two MEGs located at Hokkaido University with fiber-optic cables, since the distance between the two MEGs is only 500 m. The signal transmission latency through the cables is 4 us and the two MEGs can be synchronized within a millisecond by trigger signals. Also, the dual MEG system is equipped with an audiovisual (AV) interface based on fiber-optic transmission, which enables virtual face-to-face communication between two subjects. Unlike internet-based interfaces, the latency in the present AV interface is constant, around 100 ms. Consequently, our system will permit natural communication between two subjects, and synchronized MEG recording of their brain activity.