This study describes a brachiopod fauna, consisting of 12 species in 10 genera, from the Upper Permian (Wuchiapingian) Otori Formation of Okutadami, Joetsu Belt, Central Japan. The fauna includes a new species, Kochiproductus okutadamiensis. The Okutadami fauna, a Boreal fauna lacking Tethyan or Panthalassan elements, is the northernmost fauna of the Japanese Permian. Palaeobiogeographical data derived from the Okutadami fauna suggest that Okutadami was located at the northernmost area of Proto-Japan in the Late Permian. This conclusion supports a strike-slip tectonic model that describes large-scale sinistral strike-slip movement along the Tanakura Tectonic Line (TTL)-Median Tectonic Line (MTL) from the late Early Cretaceous to Palaeogene.