A mobile station apparatus includes a radio communication unit and a radio resource request unit. The radio communication unit is configured to be able to perform radio communication with a first base station and a second base station. The radio resource request unit requests the second base station to temporarily allocate a radio resource of at least one of an uplink and a downlink when the radio communication unit performs transmission of an uplink signal and reception of a downlink signal with the first base station. Further, the radio resource request unit makes the radio resource allocated by the second base station available for transmission of the uplink signal or reception of the downlink signal with the first base station performed by the radio communication unit.