A teaching system according to an embodiment includes an image generating unit, a start point specifying unit, a via point specifying unit, and a teaching data generating unit. The image generating unit generates a virtual image including a closed processing line set on a workpiece to be processed by a robot. The start point specifying unit specifies a start point at a position outside the processing line on the virtual image. The via point specifying unit specifies a via point on the processing line. The teaching data generating unit generates teaching data relative to the robot for a path that leaves the start point to follow the processing line by way of the via point and returns to the via point.