Appearance
The body of the fish is a red-brown color, and is spotted with white and light gray. The species has an interrupted lateral line. Its iris is yellow with a dark brown blotch.
The male C. japonicus is usually 265 millimetres (10.4 in)—345 millimetres (13.6 in) in length, while the female is 202 millimetres (8.0 in)—260 millimetres (10 in) in length. Its maximum length is 390 millimetres (15 in). The species is a protogynous hermaphrodite and a pelagic spawner.

