This paper focuses on differences in the case markers of locations where motion occurs in Early Middle Japanese sentences and categorizes such locations into routes and areas of motion. Depending on whether the verb of motion can be used with a route or an area of motion, those that can be used with an area of motion were categorized, and the methods by which they marked location were identified. The results revealed that the case marker for a route was usually wo, and the case marker for an area of motion was usually ni. Verbs that can be used only with routes were divided into two types and assessed for whether they had a high or low co-occurrence rate with routes, namely, those that take a route as an essential complement and those that do not. The findings also indicated the process of development in Late Middle Japanese through which wo gradually assumed the role of a case marker for an area of motion, for which ni had previously been used. Verbs that can follow an area of motion include verbs for which the case marker for the area of motion changed to wo and those for which it continued to be ni into Late Middle Japanese. The former are verbs that express the manner of motion, and the latter are non-control motion verbs, that is, verbs that cannot determine the arrival point by themselves.