A circuitry estimates a degree of interest in each of destination candidates for each of subject users included in a user group determined based on degree of affinity among multiple users. The circuitry sets a location in which the degree of interest of a first one of the subject users is greater than or equal to a predetermined degree-of-interest threshold value as a first destination. The circuitry provides a second one of the subject users with a first trip proposal when the degree of interest of the second user in the first destination is greater than or equal to the predetermined degree-of-interest threshold value. The circuitry provides the second user with a second trip proposal when the degree of interest of the second user in the first destination is less than the predetermined degree-of-interest threshold value.