Nipponkoku

Nipponkoku is a romanization of 日本国, the formal designation of the Japanese state. The term combines Nippon (one reading of 日本) with koku (country or state), yielding Nipponkoku as an alternative to Nihon-koku.

Etymology and readings: Japanese kanji 日本 can be read as Nihon or Nippon, and 国 as koku. Consequently, 日本国 can be read Nihon-koku or Nippon-koku depending on the reading used.

Usage and context: In contemporary Japanese usage, Nihon-koku is the more common rendering for the state’s name in official writing. Nipponkoku appears in older diplomatic texts, ceremonial contexts, or English-language writings that preserve an older romanization tradition. It does not denote a separate political entity.

Notes: The choice of reading reflects historical shifts in Japanese romanization and in national branding. Nipponkoku may be encountered in historical documents, treaties, or translations that retain traditional spellings.

See also: Nihon-koku, Nippon, Japan.