A theory of perspectivity is proposed to establish the foundation of the theory of situated agents. An account is then given, based on the theory of perspectivity, of the use of a seemingly perspectivity related expression, Japanese long-range reflexive "zibun. " The theory we proposed for perspectival mental states incorporates two independent notions, indexicality and world view. The first captures the situatedness of agents within physical environments, and the second captures the mode of reasoning adopted by agents in interacting with other agents. The relationship between these two notions were also discussed. Based on the proposed theory of perspectivity, we argued that, contrary to wide-spread beliefs, the usage of "zibun" is not directly related to perspectivity. We gave an alternative explication for the interaction of the usage of "zibun" with perspectivity sensitive expressions and the indexical pronoun "watashi (I)," in terms of the coreference rule for "zibun," the constraint on the two components of perspectivity, and the agent awareness default principle for the world view.