Legal principles governing sales under Japanese law, a civil rather than common law system, are at some significant points different from the law of the United States. The treatment accorded problems in the two countries involving impossibility of performance and frustration of purpose present good examples of the differences. Indeed the latter doctrine, frustration in the sense of the well-known Coronation cases, may not have a genuine counterpart in the law of Japan. Historically the differentiation between impossibility and frustration has been difficult enough in the common law, as casual reading of the examples used by Judge Williams in Krell v. Henry will illustrate. Japanese law, for reasons which will be illustrated below, has not experienced a similar confusion of these two situations. The American Law Institute\u27s Restatement of Contracts provides definitions in section 288 for frustration and in sections 454 through 469 for impossibility which will be useful in this paper. Our objective will be to see the extent to which these doctrines are duplicated in the sales law of the two systems and to see, where no exact counterparts exist, how similar problems are resolved