This paper shows that the principles-and-parameters approach in generative phonology can also be applied to pitch-accent languages such as Tokyo Japanese. In Halle and Vergnaud (1987), various stress patterns of words and phrases in a number of stress-accent languages have been accounted for by rules and parameters. Likewise, if we define a certain prosodical point in Tokyo Japanese as an abstract stress, its location can be predicted by the rules and parameters. Moreover, parallels and differences between the parameters of Tokyo Japanese and those of four languages (Latin, Polish, Turkish, ancient Greek) are shown with the proposed Edge Demarcation Convention within the new theoretical framework of metrical phonology formulated by Halle and Idsardi (1992).