Japan is the clear exception among the major East Asian cultures that historically shared the Chinese lunisolar calendar: China, Korea, Vietnam and Chinese communities worldwide continue to treat the Lunar New Year as their principal new year festival, often alongside the Gregorian 1 January as a separate, lesser occasion, but Japan's 1873 Meiji-era calendar reform shifted the nation's primary new year observance to 1 January outright, and Shogatsu absorbed the full traditional weight, the family gathering, the religious visits, the symbolic renewal, that the lunar festival still carries elsewhere in the region, rather than that older lunar observance simply continuing on its own separate date as a folk custom alongside the new one.
The shift was not absolute everywhere in Japan: Okinawa and some other outlying regions with their own distinct cultural history continued, and in some communities still continue, to mark the traditional lunar new year in some form alongside the now-dominant Gregorian Shogatsu, a regional exception that stands out precisely because it is exceptional, underscoring how thoroughly the Meiji reform succeeded in relocating Japan's main new year celebration to a fixed solar date across most of the country.