The Japanese term kekkyoku is commonly used to translate the English expression “after all.”  While this can result in an accurate translation in some instances, in many cases using kekkyoku to translate “after all” results in an erroneous translation.  In this paper we argue that the tendency to erroneously render “after all” as kekkyoku stems from a lack of general awareness that in addition to the usage of “after all” which is essentially synonymous with kekkyoku (meaning roughly, “in the end”), there is a separate usage which functions in an entirely different manner and has a completely separate meaning.  We refer to the former usage as the “kekkyoku (consequence) type” and the latter usage as the “konkyo (reason) type.”  When the “konkyo type” of “after all” is found in a sentence, it functions to let the reader know that supplementary information is being provided which will clarify the rationale behind an assertion which has been made in the preceding sentence (e.g. “It’s not surprising you are sick.  After all, you’ve drunk three bottles already.”)  In this case, as in many others, if kekkyoku is automatically implemented to translate “after all,” a relatively smooth-sounding translation will be the result.  However, it will be a mistaken translation.  As a case study, we examine one instance in which the “konkyo type” of “after all” was mistranslated in a published translation of a book by a sociologist.  We point out if translators gain an understanding of the nature of the “konkyo type” usage of “after all,” this kind of mistranslation can be avoided.