Data processing apparatus and storage medium

The invention discloses a data processing device and a storage medium, which can flexibly carry out a trocar service. The data processing device includes an acquisition unit that acquires shopper designation information that designates a shopper and bill data that indicates details of shopping by the shopper, and a determination unit that determines whether the bill data satisfies a distribution condition for obtaining preferential stamp data according to the number of collected shoppers. An issuing unit that issues stamp data when the issuing condition is satisfied; an updating unit that updates data of a stamp card for collecting the stamp data, which is stored in association with the shopper designation information, to a result of collecting the stamp data issued by the issuing unit; and a setting unit that sets a shop on which shopping has been performed as an element of the issuing condition, the setting unit setting a shop to be the object of the setting among a plurality of shops using any setting unit