Following Clements/eBird here treated as a race of the Ring-necked Pheasant, but often considered a separate species, the Green Pheasant (Phasianus versicolor) or "Japanese Green Pheasant." This colorful but shy bird is endemic to Japan where it is the national bird. This is a male which features a dark green body and blue neck. This group comprises three or four subspecies of which this is presumably P. c. tanensis found in central and eastern Honshu. It is characterized by being more blue, less green below. It also has a grayer, more bluish back and rump as seen here. This bird has been widely introduced and was formerly established in Hawaii where they hybridized freely with introduced Ring-necks. However in Japan Ring-necks fail and die out when introduced into the native range of Green suggesting the two are probably good species. The decline of pure Green Pheasants in Hawaii could well be a consequence of gene swamping. Canon PowerShot SX60.
References:
Brazil, M.A. (1991) The Birds of Japan. Smithsonian Inst. Press.
Giudice, J. H. and J. T. Ratti (2001). Ring-necked Pheasant (Phasianus colchicus), version 2.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.572
McGowan, P.J.K. & Kirwan, G.M. (2019). Green Pheasant (Phasianus versicolor). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/53509 on 27 March 2019).
Pyle, R.L., and P. Pyle. 2017. The Birds of the Hawaiian Islands: Occurrence, History, Distribution, and Status. B.P. Bishop Museum, Honolulu, HI, U.S.A. Version 2 (1 January 2017) http://hbs.bishopmuseum.org/birds/rlp-monograph/