Japanese exhibits a large degree of flexibility in terms of word order. Thus, not only SOV but also OSV (scrambling) and SVO (postposing) are grammatical. In terms of discourse function, there are some similarities between scrambling and (non-pause type) postposing. According to Author (2017) and Shimojo (2005), scrambled objects and postposed elements are anaphorically salient but cataphorically non-salient. Yet, Shimojo (2005: 202) observed no example with a postposed object. In order to explain this tendency, I propose that scrambling is not as costly as postposing due to the following two reasons. First, scrambling follows given-new-ordering whereas postposing does not. Second, rightward movements are more costly than leftward movements in Japanese (Fukui: 1993). Therefore, postposing is expected to be selected when scrambling cannot be chosen. As scrambling can be used for the object but not for the subject in SOV, postposing is dominantly utilized for subjects.