In Japanese a set of predicates require insertion of "~NO KOTO" to the nouns that appear in their complement position. In this paper, we examined the semantic contents of such obligatory "~NO KOTO" noun phrases through a comparison with the complement clauses that show the same distribution pattern, that is, "~KOTO" clauses, "~KA/~KADOUKA" clauses, and "~YOONI" clauses. Comparisons with these corresponding complement clauses revealed that the semantic coverage of "~NO KOTO" NPs includes not only a set of event/situation related to the preceding noun but also a variety of modality such as "establishment/non-establishment of facts" or "determination/non-determination of truth value".