To provide a bathroom system and a drain controller which can contribute to the reduction of accidents in a bathroom by easily installing them in the bathroom.

A bathroom sensor 15 which detects the movement of a bather P in the middle of taking a bath and outputs an abnormality detection signal X1 when the detected situation corresponds to an abnormal situation defined in advance is installed in a bathroom 12. A drain controller 16 receives the signal X1 and outputs a control signal X2 for controlling a drain cock 14 for draining hot water W in a bathtub 13 to a drain cock driving device 17. The driving device 17 receiving the signal X2 drives the drain cock 14 to be open. Since the hot water W in the bathtub 13 is drained through the drain cock 14 as the result, it is possible to reduce possibility that the bather P fallen into unconsciousness in the bathtub 13 is drowned.