The beginning of the Japanese Upper Paleolithic has mainly been examined using two major models: the Middle Paleolithic evolutionary model within the archipelago and the continental Upper Paleolithic diffusion/migration model. However, recent archeological data from Japan and nearby countries are challenging such simple models. This paper critically reviews previous chronology of the Japanese Paleolithic, including possible Lower and Middle Paleolithic (LP/MP), and attempts to show an alternative model of the beginning of the Japanese Upper Paleolithic. This paper suggests several possible specimens of LP/MP and recommends further geoarchaeological investigation to understand the reliability and cultural relationship between possible LP/MP specimens and the Early Upper Paleolithic (EUP). The start of the Japanese EUP is presently characterized by a flake industry with trapezoids and denticulates around 39-37 kaBP cal on Paleo-Honshu Island, which has partial resemblance with contemporary assemblages in China and the Korean Peninsula, although trapezoids are endemic only to the Japanese EUP and may have derived from the ancestral lithic tradition. Blade technology appeared earliest on Central Paleo-Honshu Island, about 1000 years later than the earliest flake technology. Although blade technology may have originated from the elongated flake technology of the previous period, the sudden simultaneous emergence implies that it diffused from the Korean Peninsula. This paper proposes that blade technology from the Korean Peninsula arrived on the northeastern Paleo-Honshu Island, including the Japan Sea coastal region of western Honshu, rather than the southwest, where flake technology long prospered, due to differences in ecological settings and adaptation strategies between the two regions.