Uncommon throughout Japan, this secretive and seldom seen rail has been split from the Western Water Rail (R. aquaticus) based on significant differences in plumage, vocalizations and genetics (Tavares et al.). Main difference visible here is the broad brown eyestripe and darker crown of present species. Canon PowerShot SX60.
References:
Brazil, M.A. (1991) The Birds of Japan. Smithsonian Inst. Press.
del Hoyo, J., Collar, N. & Christie, D.A. (2019). Eastern Water Rail (Rallus indicus). 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/467249 on 2 April 2019).
Tavares, E.L, de Kroon, G.H.J. and Baker, A.J. (2010). Phylogenetic and coalescent analysis of three loci suggest that the Water Rail is divisible into two species, Rallus aquaticus and R. indicus. BMC Evolutionary Biology 10: 226