We have developed a surgical skill training system for endoscopic paranasal sinus surgery which supports remote training and self-teaching. The key technologies of this system are HyperMirror (HM) and precise models of the human paranasal sinuses. HM is a virtual mirror wherein one’s own reflection and a remote partner’s reflection are displayed as if they are standing side by side. During training in surgery, the instant feedback from HM enables the trainee to clearly see the differences between his own movements and those of the remote expert.