Previous research indicates that people implicitly prefer self-chosen objects to other chosen objects, even when both kinds of objects are in their possession. Extending this finding, we investigated how the number of choice options and independent vs.interdependent social orientations affect this choice effect in Japanese students. Using the implicit association test, we found that self-chosen possessions were implicitly preferred to possessions chosen by others. Furthermore, this choice effect was larger when participants selected items from a large array of choice options (30) compared to fewer options (12), reflecting positive consequences of their own choices from a larger number of options. Moreover, the effect of the number of choice options on the choice effect arose clearly when participants ’ levels of independence were relatively high. We discuss the implications of the present findings for research on choice, its contexts, and social orientations.