Ranchu Lover,
You posted a pic of an OYA which a lot of us here don't have the fortune to own such big fish. Maybe we can start with Tosai class.
I have attached a link here for pictures of tosais in the AJRS 2003.
AJRS 2003 Tosai Class Winners (taken from another website)
As far as I can observed, most (if not all) of them have well defined and developed head. The headgrowth is so well grown that the eyes of the ranchu is almost invisible when viewed from the top (what I termed "embedded" or "sunken" into the head). The fishes have thick backbone, good tail seat and large tail. Some tails are quite big as compared to the body size but I guess this will balanced out as the fish grow bigger and older. Scaling is not very clear in these pics but on a few pics, you can tell that the scales are quite small, neat and well organised.
Last but not least, the swimming posture of the ranchu is important but can't comment here as I only have static photos.
