Abstract: The present invention obtains a rider-assistance system and a rider-assistance method capable of appropriately assisting a rider, an interface device used for such a rider-assistance system, and a control method and a control program for such an interface device. A rider-assistance system (1) that executes assistance operation for a rider of a straddle-type vehicle (20) includes an interface device (10) including: a guidance section (11) that provides guidance on a purchase of a function for the assistance operation by the rider; an acceptance section (12) that accepts the purchase of the function by the rider; and a communication section (13) that directly or indirectly communicates with an external system (100) wirelessly, the external system (100) including a charging section (101) for the purchase of the function. The acceptance section (12) sets a limited use-by date of the function and accepts the purchase thereof.

Abstract: The present invention obtains a rider-assistance system and a rider-assistance method capable of appropriately assisting a rider, an interface device used for such a rider-assistance system, and a control method and a control program for such an interface device. A rider-assistance system (1) that executes assistance operation for a rider of a straddle-type vehicle (20) includes an interface device (10) including: a guidance section (11) that provides guidance on a purchase of a function for the assistance operation by the rider; an acceptance section (12) that accepts the purchase of the function by the rider; and a communication section (13) that directly or indirectly communicates with an external system (100) wirelessly, the external system (100) including a charging section (101) for the purchase of the function. The guidance section (11) changes the guidance according to personal data of the rider.

Abstract: The present invention obtains an assistance system capable of assisting with function setting of a straddle-type vehicle by a rider, a portable wireless terminal used for such an assistance system, a control method for such an assistance system, a control method for such a portable wireless terminal, and a program run on such a portable wireless terminal. In an assistance system (1), an acquisition section (51) of a portable wireless terminal (50) wirelessly acquires information on the function setting operated on an input device (11) of a straddle-type vehicle (10), and an input section (52) of the portable wireless terminal (50) provides a guidance corresponding to the information on the function setting operated on the input device (11) of the straddle-type vehicle (10) when accepting the operation of the function setting by the rider.