A study of reciprocals in Japanese compares two kinds: (1) a verbal suffix "aw"; and (2) an NP argument "otagai." Although "otagai" appears to be taken care of by syntactic binding theory, it is proposed that there is no evidence for the existence of a syntactic position of the object NP in the case of "aw." The suffix can be characterized as operating on the argument structure of a verb and preventing the theta role of the object NP from projecting into a syntactic position. Based on this conclusion, it is argued that the so-called ECM construction and the o-causative involve an NP object outside of the complement clause, and that an o-marked NP that appears in the "aw"-construction is not an argument of the stem verb, but is an adjunct related to the absorbed argument. (Contains 18 references.) (Author/MSE)