A BAN system includes multiple terminal apparatuses connected by wireless communication, where a terminal apparatus of the multiple terminal apparatuses is configured to identify in which direction acceleration has changed, the direction being identified based on a measurement result of a sensor of the terminal apparatus, the sensor being configured to measure acceleration; and to refer to information that specifies corresponding to places where the plurality of terminal apparatuses is to be attached to a body, directions in which acceleration changes when the body performs a given behavior, and determines based on the identified direction, a place where the terminal apparatus is attached to the body.