When reading sentences with an anaphoric reference to a subject antecedent, repeated-name anaphors result in slower reading times relative to pronouns (the Repeated Name Penalty: RNP), and overt pronouns are read slower than null pronouns (the Overt Pronoun Penalty: OPP). Because in most languages previously tested, the grammatical subject is typically also the discourse topic it remains unclear whether these effects reflect anaphors' subject-hood or their topic-hood. To address this question we conducted a self-paced reading experiment in Japanese, a language which morphologically marks both subjects and topics overtly. Our results show that both repeated-name topic-subject anaphors and repeated-name non-topic-subject anaphors exhibit the RNP and that both overt-pronoun topic-subject and overt-pronoun non-topic-subject anaphors show the OPP. However, a detailed examination of performance revealed an interaction between the anaphor topic marking, reference form, and the antecedent's grammatical status, indicating that the effect of the antecedent's grammatical status is strongest for null pronoun and repeated name subject anaphors and that the overt form most similar to null pronouns is the repeated name topic anaphor. We discuss the implications of these findings for theories of anaphor processing.