This paper investigates into the structure of noun phrases in Japanese, focusing onissues surrounding a subtype of the particle no in standard Japanese/Tokyo dialect andits equivalents in other dialects. Based on but extending Saito and Murasugi’s (1990)insight, I will claim that there is a functional head D which functions as the “potentialnull nominal complement licenser” in Japanese, apart from a D as the locus of the genitiveCase marker. In so doing, I will put forth a PF licensing condition on the structure ofthe DP and a PF economy condition on lexical realization, discussing some of the consequencesof my proposal as well in connection with two types of the complementizer C andvarious constructions related to the particle no in Japanese.