UE receives a mobile operator policy including flow identification information, access system identification information, and a degree of compulsion from an ANDSF, and in a case where the degree of compulsion included in the mobile operator policy is a degree of compulsion that compels the UE to perform switching, transmits a request to forcibly switch a communication path used flow communication corresponding to the flow identification information to an access system corresponding to the access system identification information included in the mobile operator policy. As a result, by transmitting an MO policy from the ANDSF to the UE while the UE connected to a first access system is performing data communication, the UE changes a UE policy to the MO policy, thereby providing a mobile communication system or the like that is capable of avoiding concentration of traffic in the first access system.